Even with the one and done rule, analytics/metrics and everything else it is still a crap shoot. Basically, the 76ers are playing a sophisticated game of roulette and the one and done rule isn't going to make a bit of difference.
The idea of telling Serena Williams, Mike Trout, Tiger Woods, Jordan Spieth, "no you have to wait to a certain age" would seem silly and there really is no difference here.
And your argument isn't a terrible straw man argument? You can cherry pick on both sides of this debate. Plenty of dudes who went to college 1+ years and couldn't figure it out.
As I stated before I am rooting for the 2 and done rule simply because it will make the college game better.
I understand the NBA angle and 5 or so years ago I was in total agreement, now that I am getting older I guess my worldview is changing. If an 18 year old wants to give it try, let them, if they crash and burn, they crash and burn. Everything evolves, scouting, player development, etc. you would get to a point where NBA teams would figure out how to scout an 18 year old. On the flip side, young people are getting more and more sophisticated you would eventually get to a point where they will be able to get a better gauge on when they are pro ready. During the process if there are a few cautionary tales, a few "causalities", so be it.