Good point. You reap what you sow.
There's a certain group of dudes who still want to pick a school, go there for 4 years, and matriculate to the NFL. A simpler and proven path and doesn't mean they won't get paid while in college. These likely tend to be more serious students.
Another group is, for whatever reason, more mercenary in the age of NIL and unlimited transfers. When you recruit a bunch of transfers, those guys are more prone to transfer again. It's like divorce is a predictor for more divorce.
Some guys started in the first group and circumstances moved them into the second group. Those are probably the best guys to get from the Portal.