I think we sometimes get caught up in the whole "gotta hit 90" thing. In truth, there are a lot of D1 programs and not so many 90mph throwers that every school has a abundance of them. We visited two Mid-majors this weekend and watched their scrimmages. They are basically a week away from their first game. Both schools had radar displays. At school one, we didn't see their #1, but did see their #2 - #5 pitchers. None hit 90. Two of them, one a lefty, sat 82-83 and hit 85 a couple of times. The others all sat at around 85 and only a couple of them topped out at 87 and only a couple times each at that.
At school two, their #1 was a lefty sitting 90 and topping out at 92. This guy was the A-Sun pitcher of the year in 2016. However, the #2 was sitting 85, topping out at 87 twice over two innings and this guy was the pitcher of the year in the Cape Cod league last summer. He had great stuff and a very quick arm, but not a 90mph guy. The other pitchers, all freshmen and sophomores sat low-80's.
After spreading them out over almost 300 D-1 schools, there aren't as many guys throwing 90 as you think. You can be a good D-1 pitcher without throwing 90+.
I agree and would like to add, in my experience, while watching my "in state" SEC program go toe to toe with a top SEC program last season, the difference was the in state had 3-90+ guys and the rest of the staff was 85-88 on average, where the top program seemed to run freshman after freshman that were all mid 90 guys and never got to the starters.