He had the build and gifts to be a great route runner but he never put in the work. He never mastered the routes, and in the NFL if you're not executing there it's very hard to get separation. And he wasn't worth much even as a deep threat because he couldn't track the ball and with his micro catch radius that's a bad mix.
IMO the dude was a bad egg. If the game mattered to him he would have developed into one of the better route runners in the league. But he just sat on his speed and it wasn't enough at this level. Also and lastly I don't know this for sure but I think he was a dumb player. Took him forever to learn what the Rams were doing under Fisher's grade school offense.
I don't know a thing about Tutu. But I think the stuff that held Tavon back probably won't apply to him. McVay does a good job screening the eligible types for football awareness and love of the game. So betting against him is probably a bad bet IMO.