At first glance what you said may have been grounded in truth but when you read it and look at reality you're far from it.
College and the NFL is two totally different animals. What works in college and what works in the NFL is different, it's ran different, there are different rules, different guidelines etc... it's just vastly different especially the speed.
At the end of the day you cant seriously believe those two stars and 3 stars that are outperforming the 4 stars and 5 stars isn't the results of the coach for the most part. We know first hand of head coaches trying to force players into positions they aren't that great at just because we need the depth that happened a lot in past regimes. We also recruited players that wasn't a good fit for the system the head coach wanted to run. How many times have we had a good QB leave and turns out they exceeded elsewhere? Way too many times that's how many. If majority of our players can't start or even be the back up for the elite teams like bama, GA, osu, etc... then what makes you think we are recruiting correctly? What makes you think we should compete with them? What makes you think we are heading in the right direction?
You're spot on about not all 4 stars living up to their ranking. Bama, osu, GA, Clemson they all go through that as well and those kids more often than not transfer out. Or sit 3 years to finally become good enough to start for their last season. Every team deals with that. However I'd put money on the coaches messing up rather than the kid not living up to the hype.