Olynyk was clearly drafted to play with Rondo. When he's right, he'll pull the power forward off the block - or he won't, in which case he'll get lots of open looks. If he can shoot a high percentage from outside, he's going to create a lot of space for Rondo to create. Since Rondo will never be a knock down shooter, I think DA drafted him with Rondo in mind.
But Olynyk hasn't played with Rondo that much. Can we let the two of them play together a little before we judge?
Furthermore, the Celtics obviously need a slashing SF, or a center with something similar to a post game. Isn't that why we're tanking? Doesn't Olynyk at PF make much more sense with players like that on the floor? Players that could make use of the spacing he could potentially create.
Obviously, he's a defensive liability, but defense takes time, and effort. He clearly needs to get a lot stronger - give him time.