Uhuh...so, based on one game you came to the conclusion that due to fact that they may make changes that make the game worse or that you don't agree with, all upgrades = bad.
1: Without regular updates at least every few months, MMO's stagnate, they don't start off with the same content a regular game has, more often than not all the money goes into servers and making the game playable first, and if the game is successful then they may be able to afford to add additional content.
2: Without regular updates at least every few months, MMO's stagnate. Oh wait, already said that huh? This time I mean that, even after they get the initial game up and running, got all the bugs tweaked out, there's only so long you can keep your player base satisfied with the base content. People get bored doing the same raid or dungeon, or buying the same stuff over and over again, if you don't add something new now and again why bother continuing play once you've reached the top? Sure, it can be something as superficial as a new class, extra levels, new monsters to fight, new loot to get. But it's better than nothing at all.
3: Content, if you got gripes with the content, you've got gripes with the content. On it's face all you're really getting in the form of expansions etc. is new stuff with different artwork and X levels added on. You're doing the same thing you've always done, now you're doing it at a higher level and in a different color. It's difficult for an MMO to make drastic changes to the game without alienating the players. It's like having a driving sim and tacking on an FPS to it, which is fine if your game started out like that, but not when you've already got an established style of gameplay. Hence the devs will only add what content fits with the game itself, sometimes they do change things a big bit, take WoW for example, in the latest expansion they added destructible buildings, sounds like it'd be tricky to implement right? Given that they can't very well redo all the old content and make those buildings destructible (similar to the way they can't have flying mounts outside of Outlands or Northrend), so this feature is incorporated into a special PvP style area without impacting the rest of the gameworld.
Not all change in a game is bad, and not all of it is good. But personally I'd rather some change then none at all, even if it takes the devs that much longer to fine out what does and doesn't work.
