"can we get back to the question, why are there no points for turning over the turtle when it clearly gives you a strong position to progress the fight? "
I think another point to be taken into consideration for this is the fact that the rules like I've said before can shape the competitor, and they try to award things that are valued in a bjj skillset. In bjj you have to deal with people with tremendous guards, so guard passing is highly rewarded. This can be an incentive in the rules to learn to pass well, which will make you a better grappler. The turnover however isn't a highly necessary skill like guard passing. It isn't even really necessary at all if you don't want to use it, so why give people an extra incentive to go from having a chance to take their back to having sidemount? In grappling, you want people to give you their back. It's the best position to take, so why award going in a different direction?