Why is the coding always so under done? Is it that complicated and time consuming or does stern need more programmers or what? Stern seem to not have too much trouble getting games out so I'm thinking lots of engineers and not many programmers. Please enlighten me.

because they can
it is easy for the buyer to update the code, so there is no reason for stern to get the software finished before the game ships

coding cost money
I have notice that each time a game goes back into production, new coding is done
therefore , the more popular a game is, the better the software will be