You're going to have to be patient if you're just waiting around until the Celtics have a superstar / franchise player.
There's just no way of knowing how they will acquire the next guy who fits that description, and even when they do, it will probably be a few years (at least) before it becomes clear that said player is of that caliber.
Just be thankful that the team we have now, though still early in the process, is reasonably entertaining. I'm glad that Ainge traded for a guy who can score in bunches and who is generally an entertaining player to watch. We've got that, at least.
I think there's significant indication that at least a healthy portion of the current roster (7-8 players) are being treated as a modest foundation of young talent, although none of them qualifies as a must-keep core piece.
So while you probably shouldn't get too attached to any one player, I think we can be thankful this isn't a Sixers-style situation where the deck chairs are going to get shuffled a lot every year as the ship goes down, over and over.