People whine about super rare mounts to the 1% raiders, but companies still do it. People will cry but they , for the most part, still play the game.
I can think of 1 in WoW, the AQ openening where 1 person out of the entire server got a title and mount. Neither of which can ever be gotten again. I don't remember hearing too many complaints about it and it didn't really effect the game nor its popularity. The items can be ilussions, mounts, tittles, hell even armor/weapons with maybe a unique effect/clicky. Doesn't have to be a uber item that beats anything currently in game.
As for events that effect people who don't want to get involved at all, could easily limit it to specific area/zone etc. But again, I've seen these events cause crying/whining, but almost every time its just words and the players soon forget about it while still playing(infamous zombie/infection event in WoW).
Hell given the general stance of this thread, ignoring the cesspool that is the "masses" seems to be the prevalent idea.