You're acting like Sexton getting the chance to start is introducing him to a crack cocaine addiction that he will never recover from.
Sexton started 10 games and he played well. The starters played way better as a unit than they did with Conley. I'm not the biggest Sexton believer, but it's not a bad idea to invest into him. Who knows, maybe he becomes a more well rounded playmaker alongside better players. I think that if you were to name something wrong with Sexton's development, it's been that he's spent too much time being the only option. If anything, not allowing him to play with other good players only reinforces his bad habits.
I think Collin is a good kid. He started his entire career until he got to Jazz, haven't heard a peak about his role being reduced. I'd be really shocked if starting suddenly changes his ego where he refuses to go back to the bench. And are we really not going to trade Mike Conley because we are afraid of Sexton turning into a Machiavellian egomaniac?