Having 1 PG (who is your best shooter no less) and then no SGs who can consistently shoot the ball isn't a great recipe, so I'll stand by the roster construction opinion. But I agree on the mentally weak comment, as well.
The pieces just don't fit. Lack of guard play means we have to play through the post so much. Your post players are typically your worst FT shooters, statistically. That is who is shooting our FTs. Gillespie has the 2nd most attempts, but the #1, 3, 4, 5, and 6 guys in FT attempts are post players including Ament. We miss a lot of FTs, no doubt, but we don't have a lot of guards shooting them, either, because we don't have guards shooting the ball. Additionally, we aren't really built to come back from a deficit because we cannot generate the extra points behind the arc. In this era of basketball, you have to have shooters and we don't have them.
There was so much more I could say in my original post, but I wanted to keep it short.