Here's a crazy idea that I haven't thought all the way through yet...
What if we kept the riding time point without backpoints, but if a wrestler gets called for stalling on top, he loses all of his riding time advantage (back to 0:00)?
I think the stalling criteria has become much more objective (especially on top) so it isn't completely putting it in the ref's hands, but it would encourage more activity on top working for a turn without penalizing a wrestler whose opponent is good at defending turns.
Again, I haven't thought this through, but it at first glance it seems that this would accomplish the same goal while still rewarding a dominant, aggressive wrestler.