In all honesty, anyone who says "wow sucks" is basically saying "MMORPGs suck". I have not yet seen or played an MMO that is anywhere near as good as WoW is. It's got the largest community of any MMO (and MMOs are heavily defined by their community), it's got more class options and possible specializations than anything I've played, it's got more bosses, dungeons, hell, even more items than every other MMO I've played.
Regardless of what anyone thinks of WoW, it is the pinnacle of MMO design, in my opinion. It took everything that was common to MMOs, and expanded upon them. No other company had the resources to create something on the scale that Blizzard did. Sure, the level scale was low, but the amount of things that you could do at a given level were far greater than most MMOs. I mean, in most MMOs, it doesn't matter what race you chose, if your at level x, you go to locaction y and level till you can finish dungeon z. WoW has options, depending on where you start, and what quest lines you want to do.
Anyway, I was gonna make another tl;dr post, but I figure I've said enough.