"But generally valid removal requests get ignored for no good reason"

That's your opinion of it (everyone thinks their own reports are valid, even though we know not all actually are), if you feel like a valid report got ignored you can message a mod about it.

"this already happens on standard posts."

True, it's also a pretty "controversial" feature and not everyone likes it. Either way, standard posts are different from forum posts. Just because something is implemented in one place doesn't mean it has to be implemented somewhere else.