First off, let me start by saying that Bosh is a great player. I'm not arguing against that. But is he having an All-Star season?
Right now he is averaging 16.7 points, and 6.7 rebounds on a very impressive .540 from the field (but when other teams are double-teaming LBJ and Wade, you are going to get some open shots).
Al Jefferson, on the other hand, is averaging almost 20/10 (19.3 points and 10.5 rebounds). He is also getting more blocks per game, and more assists with fewer turnover. Jefferson's addition to the Bobcats has helped them win as many game by the end of January as they won last year in the entire season (the Bobcats won only 21 games last year and are already at 20 wins this season).
The Detroit Pistons' Andre Drummond is not as offensively polished as Bosh, obviously, but his is the best rebounder in the league, out pacing Bosh 6 rebounds and only scoring 4 fewer points. Defensively there is no question who the better player is, and when it comes to field goal percentage, Drummond's .600 from the field is even more impressive than Bosh's .540.
The Pistons' Josh Smith is putting up far better defensive numbers, and passing numbers, though his rebounds are about even with Bosh and his FG% is obviously lower.
Marcin Gortat doesn't get as many looks at the ball, but he is one of many power forward or centers who are out-reboudning Bosh while handing out more assists and getting more blocks.
It wouldn't hurt to throw Thaddeous Young in the conversation here either, or even Spencer Hawes who is out-rebounding Bosh, and better than doubled Bosh's assist average, while also posting more blocks than Bosh.
Now, Bosh is certainly more deserving than some of these players, but at the same time, it seems pretty clear to me that coaches have just ignored the amazing season that Al Jefferson is having, and have no respect for the rebounding and defensive contributions of players like Drummond if they are going to give Bosh an All-Star spot ahead of them.
I understand the 'fans' vote for who they like, but the coaches should be a little better about their selections, instead of voting based on reputation.