Full disclosure for Pushy:
I can think of one situation where I do play to the clock. Say I lose the first set slowly but badly. Say, 2-6. And time is getting short.
If the opponents get 0-3 in the second set, my goose is pretty well cooked if time is a problem. Even if I win that second set 6-3, the opponents still have more games than I do. In that case, the only hope is to get the thing to a third set tiebreak pronto. If time is a factor, then I might as well go for winners and play crazy-aggressive because being passive will be a guaranteed loss.
I can only think of two times when I thought we needed to resort to this kill-or-be-killed stuff, though. One time we lost, one time we won. Most of the time, simply focusing on every point and winning lots of consecutive points is sufficient. If you can't do this, you'll lose.