felonius - You definitely have a point. I offered the pace/3pa averages for evidence, not as a silver bullet. You are absolutely correct, though, that the slowness of the modern game cannot be 100% attributed to any single factor. I think three-point shooting is a very important factor, though, and probably the biggest (but not the only or even a majoritarian) one. I looked at the 2012-13 season, and there was virtually no correlation between 3pa and pace in the stats (which bolsters your point). Still, what I'm saying makes sense to me, and if anything, I think rule changes, officiating, etc., that you were talking about have probably sought to accommodate a faster, three-point shooting game (hero/iso ball, etc.), but it still seems to make natural sense that, normally (and with exceptions), three-point shooting teams should play slower (fewer fast breaks). Or in other words: Add a three-point line to a game and make no other changes and you'll see less inside shooting, fewer fast breaks, more set-up time.. Don't ya think?? (Of course, this wouldn't necessarily have anything to do with the Sim...)
Either way, the three-point shooting is working well for me. I'm making 7.2 3PM per game (3rd in the league), and only 30 2pt FG per game (22nd) ! I'm only allowing 77 shots per game (1st by a mile), vs a total of 89 shots for me (2nd to last, but still a HUGE disparity). When I have way more shots than my opponent, but shoot so poorly, it's important that I frequently get 3 points instead of 2.