There's literally nothing wrong with saying that a guy that averaged 39% shooting on 8-10 shots a game for his college career is an atrocious offensive player. One outlier year where he is a literal man amongst boys doesn't sell me on his ability. Doc ran him decent minutes his rookie year, and next to none last year.
But you guys enjoy getting your hopes up about sub par G-League grade talent.
In the modern NBA, if you can make 3's, you have a role offensively. That's the idea behind the 3&D roleplayer, and more generally the concept of putting guys in roles that maximize their strengths and minimize their weaknesses. Thornwell is an inefficient scorer? Great, so are a lot of guys. Don't tell him to be a scorer; tell him to shoot the ball if he's open and pass it if he's not. He can do that, and maybe he can do that well enough to be useful given his defensive ability.