the problem is not with 2-3
its more about many people just flip there players into the zone, got bad result and think it sucks
basically there are 3 types of 2-3
1. a 3C front court line up with so so OD SF PF. This bumps up the team rating in Reb and ID but usually under perform even again weaker opponent with 2 focused IS scorer @ 20 shot+. A game with prominent IS and prominent ID translate into 2IS scorer with 16IS against 3 front court defender with ~12ID. No matter which of the 2 IS scorer against the 3 defender its always a weak match up.
2. a defense with nomral SF, PF and C. A game with prominent IS and prominent ID translate into 2 16IS against the C with 14-16. Now there is 1 comparable match up but there is still 1 very favorable match up for the offense
3. 1 super C with 2 SF. now thats a bad match up in the very center of the zone, the 2 SF is not there to defend the inside shot, they act more as a wing defender to deny pass into the lane and allow the super C inside to contest all the shot and get 20+ reb. This looks cool until u realize the salary of the super C is 100K+ and the 2 SF is 2M+ at the cheapest.
there is also the fact that the high DR for guards on offense is impossible to stop, because the 2-3 always free 1 outside player. And the entry pass is much easier to make so the favorable match up can get the ball at a good position.
if that is not enough trouble for defense, there is also the FOUL trouble factor. Many team have sub par backup. If the 2 IS scorer are with high aggressive trend then the defender can be broke apart by simple getting shot at 20+ time.