I can tell you why I had him rated low 3-4th rounder.
1st his weight was only 238 which isnt that bad, but it is a bit lighter then alot of teams want. On top of that his frame clearly wouldn't hold much more good weight.
Typically a lighter player will load water for the combine to get that weight up even more before drills.
This basic line of thinking means his playing weight is even lower and his average speed is even less not special.
He is a slighter build, and very poor muscle insertions.
He ran. 4.6 again not bad but not special.
His arm length was 32 and change. Again good but nothing special.
If you want to go top 50 you need to have something athletically special to really make it in the league.
This guy has nothing special. Not a bad player but he has no traits to ever be a HOF.