The main incentive for people to push in ESEA, is that the quickest/easiest way to generally win is to capture 5 times. Not pushing on an advantage and parking the bus only gives the enemy team time to swing things in their favor.
What you are suggesting is a high risk, low reward situation. Is there a certain time lower than ten minutes that could make the game move faster, not force turtling and not fuck over the attacking team? Maybe. But that time would be so specific on every single map and on every single point that any stalemate timer which is too long would do nothing to change how we play now (not warranting the change) or too short where it can easily do the opposite of what you want. Now if you were to get that perfect timing, if it exists, the benefit would be so negligible in comparison to all the other reasons we do play aggressively and all the other things we could change to make the game better.
So, we have a massive chance of lowering the stalemate timer to do the opposite of what the change is intended to do or it isn't going to change a fucking thing and we have a small chance, if it even exists, to make the game better by a fraction on why it is already good.