Sometimes, you have to assume that the opposing coach has a brain, too. If you pull out the post to a high post position, how many ways are there for the opposing coach to counter? Can he simply cover your post with a forward because he isn't that great of a shooter? If his post is drawn out, does he have another rebounder underneath? Will that likely give him the baseline? How do you counter his counter? If he counters with A, you have to counter that with B. But, if he counters it with C, you probably would have more success countering with D. The various options might be difficult to explain in a time out.
I think a lot of the time, the halftime is simply a chance to restore the psychology. They caught you off guard, and you didn't respond well. You are on your heels. It is tough to settle a team down with a time out. Getting into the lockerroom can provide your team with a chance to restore their emotions. That may be difficult to do in front of 100,000 screaming football fans or 10,000 basketball fans.
Already, we have seen some different halves. Baylor/Kentucky was a tale of two halves. OU/Creighton was a story of two halves. Time outs hadn't done a thing.