When you raise your FT shooting % from 65% your junior year to over 91% your senior year then you can lecture me about free throw shooting. Until then, I stand behind my original statement.
If you had any idea how hard I worked on this aspect of my game for the 8 months in between seasons then you'd understand the point I was trying to make. Every weekend... EVERY weekend I would shoot between 1000 and 1200 FTs. Three or four nights during the week I would work for 2 hours on it. I would shoot 25, do a round of suicides, then shoot 25 more. Rinse and repeat. That way I would develop consistency of shooting for when I was rested and when I was fatigued.
As somebody who most assuredly worked on this infinitely more than you did, I can tell you with 100% certainty that muscle memory is key. You can make jokes about it or belittle it all you want, but the fact remains that once I trained my muscles to go through a routine, it became almost second nature. It took guidance from my coach and a LOT of work on my part. So don't tell me that it can't be done, that one can't work and train to become a consistent 80% shooter, especially a professional player. Fact is, many don't become good FT shooters because they don't place a priority on it.