I am okay with DF, since it is part of the game and technically "vanilla"... but, I think that if there's a problem here, it has to do more with some people expecting casual/public games with random people to play out like a coordinated time attack game. They're completely different things and what's optimal for one might not be for the other. As an example, I've seen a lot of games go a lot more smoothly/quickly (because of less deaths) *after* someone stops using DF, when a FO can Resta freely. Yes, people can/should use mates, but when you join a game with random people, there are going to be people with varying levels gear, mat use, level, experience, and a bunch of other things.
I've noticed the same thing with Jellen use, because most people who consider themselves to be "good" at FO don't want to use this because of DMC. And when I'm in games who are clearly full of experienced/high level players, I try not to use it as a FO. But in other games with lower levels, I've seen a game go from extremely hectic and full of death, to smooth and painless, just because I started casting Jellen at the start of every group.
I love watching time attack stuff, because it's impressive to see, but for everyday games I've personally never considered things like constant/high DF use, or no Resta/Jellen to be optimal. But I am also fine with people playing how they want.