There are some MMO's where you hate the game AND the players
Or you hate the game before you even meet any players!
I think the anti-gamer types who think that computer games make people crazy haven't met enough people IRL. I reckon they'd find that the same people who grief in online games and generally act like jerks were like that before they played computer games, and just use them as a way to act out their pre-existing dark desires. Okay, last bit was a bit corny but you understand what I'm getting at.
So it might depend on how the proportions are for, let's call them, builders and destroyers. If there's something like 50%/50%, it'll suck. It'll either be that half the time in the game you'll have what you built get destroyed, or that some areas of the game will be unplayable because of the large numbers of destroyers there.
Moving to something like 25% builders, 75% destroyers, the game will probably become a gankfest fairly quickly with most of the builders leaving for a game where they don't lose their work on a daily basis. 75% builders, 25% destroyers could be pretty fun. You'll have to be wary of who you meet, and you'll have to keep an eye on what you've built to protect it. Might have to have town guards and whatnot. If some destroyers get organized there might be some fun attacking/defending PvP. 90% builders and 10% destroyers would be more relaxed but pretty fun too, some wariness but you'll generally be able to assume you're not going to get ganked when you meet someone randomly, and it'll be rare to have to organize a defense.
I'm looking forward to seeing how it turns out.