You're way too optimistic about Bolomboy, IMO. Please, tell me the name of one player who couldn't even get on the floor at the age of 23 and then became "very good". I think we can all agree that Bolomboy has more than enough athleticism to play in the league, but he is also slightly undersized even for a PF - he's smaller than Boozer, for instance -, doesn't seem to have the skill set to play away from the basket and is not particularly smart. By the way, he is not "only" undersized, but not physically imposing as well.
I hoped the Jazz not only trusted Bolomboy with the PF reserve role but even run some plays for him, so perhaps he would somehow develop, but I think that with Hayward gone they decided to go with Jerekbo on that role, a (somewhat) proven veteran. That left Bolomboy really at the end of the bench, where he became basically irrelevant. Besides, management may not have liked his summer league performances.