Another year of college did not benefit several of their teammates so I do not blame them a bit for leaving.
And the whole myth that they are going to go from flaming out in the league to having a career in it just because they stay one more year in college going against awful college players (for the most part as far as opponents) is a bit humorous. They are either going to make it or not make it it regardless. You either have it or you do not in sports. Lyles and Booker both have it enough to stay in the NBA for 10+ years with ease. And leaving early allows them to get that 2nd year contract earlier, which is what matters the most in the NBA.
If they had stayed they probably would have went up a few spots each in the draft, and made a little more initially, but that is it. They may have put up more gaudy numbers at UK next year, but numbers are not everything. They are going to improve regardless, and probably will improve more by going against pros in games rather than college kids IMO.
Selfishly I wish they had stayed, but it is not about me and what I want. It is their lives. I understand that, many on here do not.