Fun or grief?

So I was experimenting with the new zombie infestation world event in World of Warcraft last night. Clicked on a conspicious crate in Booty Bay, took the boat over to Ratchet, and went into the pirate area, where I turned into a zombie. As zombie you continuously lose health, unless you attack humanoids. When you kill NPC humanoids, they rise as zombies as well, and you can beckon up to 4 of them to help you. You also have a ranged area effect with which to infect humanoids, which then turn into zombies after 10 minutes.

The pirates got boring quickly, so I headed into Ratchet itself, infecting NPCs, and battling the guards there. A low level player attacked me, so I killed him. Another just stood watching, so I didn't want to attack him, but infected him anyway so he could share the fun. A while later a level 70 pally turned up and killed me, ending the zombie infestation of Ratchet.

So far, so harmless, although I'm not sure how the player I killed felt about that. I stopped mucking around as zombie and joined a Karazhan raid with my warrior. But guild chat reported lots of people being unhappy with the world event. Some players used their zombie infestation power to take out centrally important NPCs, like the flight master in Shattrath, or bankers and auctioneers. Of course the NPCs respawn after a few minutes, but lots of people get annoyed if they have to wait for 5 minutes for a flight in Shattrath. And it seems the infestation is programmed to spread, this morning I noticed conspicious crates and infected animals in the cave that is the arrival for teleports in Thunder Bluff.

So on the one side players always complain how static the game is, and want events that change the world. On the other side they complain if something actually changes, and they can't access their flight master, banker, or auctioneer NPC immediately. One guy in guild chat got so angry, he logged out. And I'm sure we'll hear a lot more complaints before the event ends with the release of Wrath of the Lich King. Are game-changing events doomed, because players can't accept any change?