I see what you're getting at. Without a doubt, at most top 20 programs, there are a solid group of athletes that do not get the first team practice experience, direct coaching and confidence building, Saturday game-time experience, and "notice"... because they are tucked behind other supposedly superior athletes. It very likely results in little or no consideration for professional sports consideration for those young men.
Naturally, for every 1 athlete in football that goes on to a professional career, there are 20 more that think they will when they get out of high school. Coaches at the top 20 make all of them think they will. They don't really know who will... so on that note, it is an "innocent" argument. I think the point you are making is that there are stronger and stronger arguments that some athletes should swing over to the mid majors and get "noticed".
In today's media market, a 5 star running back... the best in the nation... in reality... could come to UL... and go on to be the #1 draft choice in the NFL. Most would never have thought RG3 could play for Baylor and win the Heisman. The advantages in going to a top 20 team... as opposed to 40 years ago... are starting to evaporate as far as your "notice" for an NFL career. You have to get playing time and coaching. Another differentiator that is evaporating is weight training, dietary offerings and supplements, knowledge of the coaching staff, etc. Way too much game film and learning techniques are universally available to everyone. 40 years ago, there was a wide void in the top 20 and others. That just isn't the case anymore. The big difference now is spending unGodly amounts of money on accessories... and wooing the best athletes. He who has the best talent is going to win. It doesn't hurt if you've already got a pedigree of national championships either... but that too was related to the money you've had available to your program.