So the problem is not for those who are below level 60, since they can simply start from scratch without losing much other than some easily repeatable solo gaming experience, but for those who actually put alot of effort in the end-game content (either PvE or PvP) together with other people. Something that you can achieve only if you put some serious effort in the game, and you can't do it solo, you must work strictly with your mates to actually get something back from all the time and effort you put in the game.
Pre-60 content is 100% win, you simply have to put time in it and you'll reach your goal eventually. But end-game is a roulette, the stuff you want might not drop for months, or simply you don't perform good enough to deserve certain items, or your guild is not good enough to clear a raid, or something comes up in real life that stops you from being able to raid; there are so many factors in the end-game that can make you fail even if you put alot of time and effort in the game.
I consider myself a casual gamer compared to most of the vanilla players, so I don't give a rat's ass about K1 falling down; since I play on private servers for a long time now, I've learnt to not get too much attached to my characters and to not put too much extra effort into them like getting all repuatations to exalted, getting all recipes/patterns, 300 fishing skill or whatever useless and crazy stuff we geeky people do on retail. Becouse what's happening now to K1 will eventually happen to any other present of future private server. So just play for fun and you wont have any regret.
Anyways the point is that the pre-end-game characters should be at the bottom of the transter list. Who really deserves to play on a more alive server are the people who put the real effort in this fucking game, those people who actually clear the end-game content non-stop for the past year and a half. Without them all that sweet blizz-like scripting would be wasted.