It's a matter of numbers (officials) and rules when you compare hurry-up offenses in college vs. high school.
In NCAA, you have seven or eight officials, and ball boys who are old enough to know what they are doing. They are able to switch balls in and out and get the ball spotted quickly.
In HS, you only have five officials, and the ball boys often are kids with the attention span of a piece of linoleum. Trying to switch the ball in and out is often an adventure, so spotting is sometimes delayed while a ball is being secured.
In NCAA, teams get 40 seconds from the end of the previous play to snap the ball (unless there is a penalty, etc.), so as soon as the team can get up over the spotted ball, they can snap it unless an offensive substitution occurs.
In HS, the ball is not to be whistled ready for play until after it is spotted and the white hat has confirmed the down and that the rest of the officiating crew is ready to go.
In other words, NCAA rules and game management are a little more 'user friendly' for fast-tempo offenses.