3 and D guys make a fortune in today's NBA. Tyler is tall and can shoot well, which are two important attributes to being a good NBA roleplayer, but there are so many aspects of his game that have a long way to go.
It's important to remember that in the NBA, even the roleplayers were superstars in college. Remember Semi Ojeleye? He absolutely destroyed the AAC that one year - conference player of the year, good athlete with an almost LeBron-esque build, good defender, shot 42% from three, high IQ, etc - and is only barely in the rotation for the Celtics three years in.