I think you're being a bit naive there, Herschel. The people who run WotC are gamers as much as you and I are and they will have the same kind of history of creating and DMing and playing in homebrew games and campaigns and campaign worlds. The campaign worlds that are officially supported now (PoL, FR, Eberron and Dark Sun) started out as someone's homebrew world. It is short-sighted of them to say the least to think that all players, not even a "significant portion" but all of them, play in one of their published campaign worlds.
LoL, you're making some rather large false assumptions.
1. You're assuming the game design crew is working on the character builder. They're not. It's farmed out either to internal IT or a third-party software developer. (Notice your DDI subscription reminders, etc. go through Digital River?)
2. This means the design crew lays out what they'd like to have the product do and don't have direct control of the project. The programmers then try to provide what an intermediary said the design crew wanted.
3. You're also assuming the software people just do what they want when they want. That's not how it works. When you have a program database like the Character Builder, upgrades are categorized and prioritized because there's a time and money budget. This usually means...
4. Initial plan, followed by deadline, followed by compromise as everything (feature-wise) can't be ready and tested by deadline, followed by rollout where numerous bugs are discovered that would never show up in QA testing. These bug fixes become priorities in program updates.
5. After bug fixes and data updates, the next priority is usually core functionality improvements. Then tertiary functionality improvements within the system. Then oh yeah, it also has to be able to integrate with the Virtual Tabletop in development. All these things take time and money from the budgeted allotment.
6. After all of this is done, if there's money/time left over for the project (after making a reasonable and desired profit also) then things like customization may be put in. And that's not accounting for any work stoppages due to contract issues or whatever.
It's not a simple, quick or easy process, especially in a corporate structure. Them's the breaks, deal with it.