Apparently the OP doesn't understand how software development works for massive multimillion dollar projects. It is much, much harder to push incrimental builds, especially before you're completely certain how one new feature might affect or be affected by another, especially if you seperate them to implement in different patches.
(due to posting restrictions)
I don't know other games that do it. Not MMOs anyway.
Every MMO has major patches that include a collection of content and fixes, and sometimes minor ones for EMERGENCY hotfixes. No MMO I know of does patches to release features individually.
In fact, I'm informing you you should raise your expectations, not lower them. "other games" that aren't MMOs are smaller and have fewer features to begin with, so there is both less to break and less to implement in order to make it happen. Again, you understand nothing about what it takes to manage such a massive project as an MMO.
Tell me, when was the last time WoW made a patch to add one, meaning singular, brand new feature to the game. I Don't know of a time this has ever happened. New features are always added in major patches, not individually by themselves.
It's clear to me though, that you're intentionally not getting it in order to black-knight bash the development team. But I could be wrong. Maybe you can link me to an official patch notes page for a major MMO we've all heard of, that includes nothing but a single feature addition with no other content or fixes, and one that does this on a regular basis.
All projects are developed differently though, so even if you did, the argument "So and so does it, so they can do it too!" is a logical fallacy. (Oh yeah, and anyone who liked the post below also has a similar lack of understanding about how patching major software pojects works)
-edit again- OH, one last thing. Do you realize how many people it took to make this game happen? This game has like the world's longest credits roll in the history of gaming. It takes more than one person snapping their fingers, going "BING! feature done!" *snap* "uploading patch!"