This, kind of. We held all of our opponents under 100 points during our 5 game win streak. I thought our defense was more disruptive when Aldridge was out, however, I think that was more a side effect of us being undersized than Aldridge being sucky.
We had 4 guys on the floor who could switch amongst each other and we wouldn't have too big of a mismatch. This led to quicker rotations, quicker double teams, and more steals/deflections because our defense became more aggressive to try to mask the lack of size. I think it made us tougher to read. We played a style of defense more similar to Miami.
With Aldridge back in, we play much more conservatively because he can't guard anyone but his man. We don't want him leaving his man, and of course Lopez has to stay on a big. That leaves our 3 perimeter players to cover the entire 3 point line where Stotts tells them to stay on shooters. So we are back to the "strategy" of having everyone stand and watch someone else get beat off the dribble or a ball screen, and hope the offensive player misses because we can't leave our man for fear he might get a 3 point shot...
TL;DR I thought our D was better without Aldridge because we changed our style, not because Aldridge is a terrible defender.