I have never seen to much use in TNT. i will review the places where i find it useless in a nice list.
1. GRIEFING.
for me, griefing is boring. i am not a sociopath who enjoys blowing up other people's art.
2. MINING.
i am very conservative about resources. therefor, the low drop rate discoureges me from TNT mining. 
3. MOB BATTLING 
WOW! what a UGLY crator! pluse, when i battle mobs, it is when i am defending a village. seems crazy to build them houses, then blow them up.
lastly, 
4.BLOWING UP MISTACKES IN CREATIVE.
TNT is just not powerful for this. i made a HUGE boo-boo once. i tried to grief it, but it took way to long to get anywere. further made a macine that constantly summoned TNT, and still was too slow. eventually i just used MCedit and erased the whole thing.
however, the one use i have for TNT in creative mode is by making a cave or large space for building hidden gizmos in caves when you need one.

this was my first blog, just because I dont see why TNT is idolised in minecraft. leve a comment if you want to argue, but plese don't hate. NOBODY apritiates it. (i might need a grammer nazi over here. as you can see, i am VERY bad at grammer.)