Pushing away "casual" players is part of the goal. if your just there to play around on you off time, maybe staying or maybe not, then we don't need you on the server.
The deathbans definitely can't be super large, however, if they are large enough they keep away the players that you don't want on the server. The point here is that we want mature, skilled players. A mature skilled player(who is interested, of course) will only see the deathbans as a significant setback when they die, giving them more incentive to do well. It can also either increase or reduce violence, because players either know that it's not good to die or they see it as an additional reason to kill their enemies.

I don't know why people think "Oh, I die and can't play for an hou(or a day, etc.), I'd get frustrated and move to a different server. I play Minecraft to goof around and have fun doing whatever with my friends, not get really into the game and get good at it." Really, anyone who is not willing to

• Be Mature
  
• Practice and take time to get good at it
  
• Actually use the server as it is intended to be, as a game that you need to get good at, rather than another world with fun content to mess around on
  
• Realize that the deathbans are a double-edged sword; pushing away newbs, scrubs, and the like, while attracting the players that it would actually be fun to play with
  

does not deserve to be on the server. Which is basically what the deathbans do -- get rid of all players who fail the above test, without me banning every single one and ruining the reputation of the server because "the owner bans people he doesn't like." Also, the intended crowd isn't casual players, it's hardcore, into the server players who like it, are loyal, and don't mind the deathbans. EVEN if the deathbans were 15m, you'd feel the same way.

Also, you are making a stereotypical assumption -- that all Minecraft players are fat 12-year-olds. Fat 12-year-olds like it easy because they don't understand what a challenge is. In their minds, anything hard is evil because they can't do it, and they're too flippin lazy to put in time to learn to be able to do it. If all Minecraft players were fat 12-year-olds, then this idea would never have existed, because I would be a fat 12-year-old. And just because you're not fat and 12 doesn't mean you don't have the exact same flippin mindset as the rest of the scrubs who are.

It seems to me that the deathbans are already doing their job : keeping the people it isn't fun to play with off and far away, living in their little Pokeman or faction servers wasting their life and money away.

Also, here's an alternative to deathbans, if that would interest players more.

Of course the deathbans would be balanced enough to not make the server unplayable. That exact plan could be set up as "1st death: none, 2nd death: 5m, 3rd death: 15m, 4th death: 30m, 5th death: 1h, 6th+ death: 2h"
That would cut the unwanted immature players while still allowing skilled players to play.

i.e. Say you had the best set of gear on the server, but you fell into a trap and it killed you. Some players might get angry and need some time to cool down, and deathbans automatically gives them that time while keeping others from the anger, and it prevents it from snowballing(they get mad and cuss in chat, getting them muted, making them madder. This would snowball until they leave for good).
It has its perks against players with anger management problems but are otherwise mature.\

i.e. Say you have a base and it's being raided. Assuming you have a stash(homes may or may not be included in the server), without a deathban you could reequip yourself and dash back to your base, giving whoever is raiding a disadvantage because of the many lives you would have. Of course, having no homes would fix this, but allowing players 2-3 homes will get more players on, as they are fairly standard in normal survival servers, whether it's factions, towny, or something else.

Also, many people see deathbans as inherently "bad." While it does make sense that they are worried of a lack of play time, if you are skilled enough then the only real reason you would die is when experiencing a new enemy or fighting another player, and even then not all the time if you have a decent amount of skill and gear. I have found that many people actually like them as well, so it can be a selling point on the server.

And if someone "rages and never logs in to the server again" then they are probably immature and then the deathbans have just done their job -- keep immature players who would plague the server and make it less fun off the server, without screening them and hurting feelings by banning them for something so trivial as "complaining that they died and they want their stuff back." Banning for stupid things would kill the server, while deathbans only screen out the scum of the Minecraft community. And while some see running a server as a business venture entirely to get players on and donating, I prefer having a server that not only pays for itself and is fun for me and my friends to play on, and immature players can ruin the experience of mature players.

Many people feel that way. That is why it would be targeted towards the mature players -- they understand the necessity of a challenge. However, there is a reason that the proposed system is the way it is -- if you've died once or twice, the deathbans simply server as a short break for you to grab a snack, use the bathroom, and plan for your next move. Afterwards, once you've died enough times, it would really keep players out. The only problem here is that unskilled players will never get to the point where they can stay alive for a period of time long enough to partially negate the loss of a deathban. I have found, however, that unskilled players are also immature and therefore aren't the wanted crowd.

I have previously run a server with deathbans. It was quite similar to this idea, however, I had no time to successfully advertise and it didn't do too well. I did, however, find that players who did get on were very skilled, mature players(with the exception of some weird caps levels in the chat) or they were my friend(some of my friends are immature, I keep in touch because of my lack of easy-to-get opinions).

It does work, however, it requires significant advertising. I asked here because I want to know if players would like a server like this, and if enough liked it I would begin work.

Also, I am slightly eccentric, so content may or may not range from Demonic Sheep terrorizing the world to firearms. Also, this is part of why I like the deathbans -- they're fun for me.

The time travel/purge/world regen could be quite interesting.

Of course, there would be a spawn, and a low-ish quality kit available that would really only be useful in the case that you just died.

Also, anti hack plugins and active staff as well as some rules would keep unfair advantages off of the server. I find that hacks are not only used by unskilled immature almost noobs, and they are not only hard to use but require a far better computer to be able to stay on the server( I know this because a couple of my friends kept forgetting to leave their hacked clients off when they joined, as they liked hacking on other larger servers).

I have found that suddenly dying is annoying, and spawn would be designed accordingly. Of course, the deathbans system could be changed if that's what the players want, I just prefer to keep it for aforementioned reasons.