Blowouts

on 2k10 when ever i was blowing the cpu out they always kept there starters in while my team sub my 5 out... i was wondering did they address this for 2k11

What's to address? The other team still has a chance to comeback, especially with 5 starters playing 5 reserves.

Generally speaking when the game is out of reach, the starters on both sides eventually get pulled and the game enters "garbage time".

It's a problem in 2K10.
To think that it worked somewhat okay for 2K9 in playing scrubs for the final two minutes when the cpu has a blowout loss.
On the other hand, the sub logic works in 2K10 when the cpu plays its scrubs if they have a huge lead in the final three minutes.

For comparison's sake, NBA Live 10 was a little better in that regard as well but you'd still see some starters out there when normally you'd expect them to take a seat. We were told in our Q&A that substitution logic has been refined in NBA Elite 11, I'd say there's a chance that NBA 2K11 has likewise made some tweaks.