An extra 3 feet does not give your brain that much more time to decide whether to lay off or not. If hitters are laying off of the rise ball a lot, then the pitchers rise ball is not good enough. DD has them both and throws them both....a lot. The rise ball is a scholarship pitch. If you don't have one, chances are your not going to pitch in college and be successful....JMHO
I'll agree that the extra 3 feet doesn't give a huge advantage for reaction time. However, a batter laying off a rise may not be entirely due to the quality of the pitch. The batter may have put a lot into vision training, which gives them an advantage for pitch recognition. Also, lots of pitchers/catchers get into a bad habit of rhythms and patterns. A smart batter knowing what pitch to expect, combined with great pitch recognition skills can easily trump an average rise ball pitcher.
I'll take a well thrown drop for younger kids until a decent rise is developed. A peel drop is very effective when thrown with great accuracy. But it must be thrown unpredictably.
Not true that a college pitcher MUST have a rise. Several of DD's team mates didn't really have an effective rise, BUT they made up for that with lots of other stuff. Comparable to saying a MLB pitcher MUST have a 90 mph fastball - we all know that's not so.