Did I just hear you say that you have to turn down millions of qualified average size men, but only hundreds of extremely tall guys with equal talent, to fill NBA rosters? Yes, I think I did, a reworded direct quote as sure as a sure thing.
Now extend the logic. Of the millions of average-size men who have the same quickness, dexterity, and leaping ability (distance from foot to ground) that the hundreds of extremely tall guys have, don't you think that maybe 1% (maybe even more) of the millions of average-size men will have such extreme talent that you could say they are more talented than the extremely tall guys who made the league?
So while GMs routinely turn down 99.99% of average-size men, but only maybe 99.0% of extremely tall young men, in order to fill their rosters, you say that the GMs are not discriminating by height, even though you want to evaluate purely by talent and would not personally turn down all those young men. There is a mind-boggling number of men, but too little time. So it seems I have proven that some things in history do not change, and GMs do indeed discriminate by height and do not choose the absolutely most talented players in every draft selection.