That strat you have doesnt seem very fun to do every time. And i do that, but i still dont see it as fun.They can lock it if that's what you want.
P.S: You can win in OP if you just rush every single team ASAP. OP games aren't as long as you think if you play it correctly. It isn't the worst or best game mode at all but it can't really be changed.
It isnt the worst, but it isnt the best, either.
However, it isnt that it CANT be changed, it is that nobody will let it be changed, not even CC. They get too much money out of it to make a risk like that, even if its quality is low.