And haven't many people argued that Twitter did this exactly right? The idea being that they did one small and simple thing, provided a generous and open API and then let other people help bring interest to them?
A glaring example of how little Twitter has done to support developers since their original API is this support ticket that has been open for about 15 months: http://code.google.com/p/twitter-api/issues/detail?id=214
Obviously, those 150 people have been working hard on something for the last year, and providing the best tools for developers (let alone filling huge holes in their API) doesn't seem to be the top priority.
I could be totally wrong on this and API V2 will be out in a few weeks and blow all of our socks off.