Nothing CTJ said do I disagree with. Having just completed this whole process, I could go on for days about this stuff. A couple of things that became obvious to me. First, coaches are looking for players who are physically ready RIGHT NOW. These are the kids who when you see them, they look like they are physically 30 years old. Sure, they have to project positions like OL and DL more than others, but they want mature bodies now (this may be even more so in baseball).
Second, you are at the whim of the evaluating person in "the system" and all their good and bad traits/qualities. A lot of preconceived notions of the evaluators simply will not be overcome. This can be infuriating because, like it or not, it is part of the system, and it affects the player.
Yes, stars matter, absolutely. But it is still a crap shoot because they can't dig deeply into backgrounds. Percentages say that 4* and 5* are more likely to pay off and they do. Coaches who are good evaluators will have a mix of 2-5*, even though fans complain that they are taking "bread." Smaller schools will be between unrated and 3*.
Fans complain all the time about the services, recruiting evaluators, etc., but at the same time believe the bigger "system." It's a pretty interesting dynamic.