Genuine question: what don't people like about munchkin? I know it's quite luck-based but I have always thought it to be ok. I haven't played it a huge bunch though.
In most games, the mechanics of the game naturally lead the game towards its end. It creates a sense of urgency, where your time is valuable and you have to be careful about what you do with it. No matter who is playing the game with you, there's a game clock and there's a purpose to everything that happens. In Munchkin, the mechanics of the game lead you to drag out the game as much as possible; what most people consider to be the mechanics that make Munchkin fun are the same ones that take a game situation and drag it out for a really long time in a really not-fun way for absolutely no reason. You get ahead because someone chose you to get ahead for a non-game-related reason but you get set back by game-related reasons, which makes the game not fun; if the game took 10 minutes and you could play 5 in a row that might be fun, but you can't because the game takes 3 hours and most of the time you aren't actually doing anything, you're watching other people do things and feeling left out.
There's also the part of the rulebook that basically says "we know we didn't write all the rules to this game because we're too lazy. If something comes up that isn't covered by the rulebook, the person who owns the game just gets to decide." This is not only complete garbage, but offensive to everyone who's ever made a board game, played a board game, or bought a board game. How anyone would pay money for a game that up-front admits this and make no effort to fix it is beyond me.