Proponents of any style have to recognize their limitations. Setting-oriented DMs shouldn't do information - there are far more effective ways to engage players by dribbling out setting details gradually, so players have time and inclination to process them. Similarly, hack'n'slashers shouldn't be killer DMs, role-players should make sure that everyone gets a chance to RP, and that the RP is not just stream-of-consciousness inside characters' heads. And no one should railroad too much. But there are pitfalls in each variety - it's not something unique to the "social" DMs.
Sure, there are a variety of players and styles. But I really see no problem with voicing a preference. Players should be accommodated to the degree necessary, but if styles clash too much, sometimes breaks will happen, and there is nothing wrong with seeking out the kinds of players you want for the game you want to run (assuming you can find them). Saying something is badwrongfun means you think that a particular style has no place in the game, and that other people shouldn't promote it, either. Having a
preference for your game says nothing about how others should play. It doesn't even mean you won't play in murderhobo games if you happen to prefer running social games. I actually like the tactical side of the game, but I don't see why that has to be identical with hack'n'slash. It can easily be balanced with a social game.
On the whole, the murderhobo game isn't really an endangered species, such that it needs to be protected. Of the three legs of the game (mechanics, RP, and world design), the latter is by far the most neglected, so to me, emphasizing it is just restoring balance.
The question is, when does it stray from giving players choices toward imposing a game style upon them? A GM who buries players in complex setting histories and character interconnections when all they want is to go out and hunt orcs is doing them a disservice - just as a GM who only provides nothing more than a straightforward dungeon crawl is doing his players a disservice if they want a rich and detailed gameworld to explore.
And since humans are complex and varied, not only may you have both types of player around your table at the same time, but the same player may be looking for one experience from a particular campaign, and the other on a different occasion.
There is absolutely a place for a whole spectrum of playing styles, and groups of players should feel free to explore them. But starting from a position that the simpler, more gung-ho 'murderhobo' style of play is badwrongfun that players need to be weaned away from is an arrogant and presumptive position that does them no favours.
