I'm pretty sure they want to get it done as much as we want to play it. I really doubt they are not releasing just to anger the community, what would be the point in that?
Also, in all this time, I really doubt they are programming every single day. You have to factor in things like boredom, frusteration, team conflicts and just general rl issues. I would love to be able to play mta right now, but if they gave in and released it right now, obviously it wouldn't be ready enough to be enjoyed, odds are we would try it out and then just spend more time waiting for a patch to fix the things that they didn't have a chance to alpha test.