It could be because of one or more of the following reasons:
A. We want to see you get so excited before release that you will need towels on the floor near your seat when we DO release. (not that you won't need towels for that reason anyway)
B. One or more of the team have (had) a real life situation where the creation of win and awesome simply didn't rank as top priority. (I know it's impossible, but it happens)
C. We are sadistic bastards.
D. Making sure there are no bugs and as few flaws as possible takes a good amount of time.
E. All of the above.
.... patience is a virtue....