150 plays with 10 special teams plays or even 20 is still putting both teams at 60-70 offensive plays which is simply outrageous and not reachable. The rule difference in college has nothing to do with it, you are still talking about 5 full minutes per quarter which is 20 minuets a game longer which far exceeds the amount of times someone goes out of bounds.

The fast tempo spread offense is starting to lose its shine in college and will soon in high school. The official holding up the start of a play till the defense gets subs in is a factor. Defenses are getting better at containing the fast play air raid also.