I agree with you on a lot of points: this game is great, but yes, it does have some issues. I think it's right to point out that these things (content creation and fixes) are not two sides of the same coin - they're different coins. The writers aren't going to fix the ability delay, and the environmental designers aren't going to balance PvP. There are many different positions in creating this game, and they have different roles.
I'm not going to pretend to understand how developing TOR works, but I get the feeling that the positions are segmented enough as to allow one group to fix the game, while another simultaneously adds content. It makes complete sense for them to work on issues and also work on more content. Why would they, as a business, work for weeks "perfecting" the original and consequently leave those who have already experienced much of the content? It doesn't make sense because they would lose subscribers.
I'm personally not worried about the direction the developers are taking the game in regards to your questioning. We've already seen a rapid deployment of hotfixes and patches, and as of 1.1, fantastic additional content. Hell, even the video added today shows a lot of promising content (finally some Legacy customization!). They're juggling the two tasks quite well.
Edit: I guess I should check the name of the poster more often. Heya Mord!