strong above the rim, possibly in traffic then your argument would be exactly right. He doesn't do those things well. Fouss has a nasty post game and is very crafty around the rim when guarded by a single defender, no matter their height. Usually needs the ball and his back to the basket to get going. Can we argue they have the same advanced defensive stats? Sure. Can we argue Fouss is a better offensives threat and will probably score more than Keita? You bet. What we can't argue, is that in a modern, high level offense, Fouss fits better than a strong rim runner with plenty of verticality and athleticism. Just how it is. Again, nothing against Fouss and he'll get his minutes and points. Just in a different lineup and with the coaches picking his matchups.

Disclaimer: I am not at practice, or in meeting rooms, or watching film and game planning. This is all my own opinion.