I don't know if it's fair to generalize and say that people in a particular area would absolutely get mad if Bobby was outed on the show. I think you may be right in suggesting that TPTB cut the scene because they thought there would be a backlash. But you might be surprised. People might be more tolerant than you think, even if they live in the Bible Belt.
I will agree that not every person who lives in the bible belt is homophobic, but I do think there are a number of people that would be uncomfortable with the idea. A while back there was a series of articles in the Washington Post that talked about young gays in the "bible belt" and American heartland. Take a look at the laws being passed to prevent gay marriages. Homophobia (like other prejudices) is very much alive and well in the USA. True, there are more and more people who don't have a problem with it, but it still a issue.
That said, I don't think that people at CSI would let what people in the heartland stop them. (I mean how many kinks have we seen on this show?) More likely it was there was not enough time in the episode, and something had to go. As Bobby is not a regular character, his personal story, unless it was directly related to a case, it would go. Also Bobby is only a recurring character...so if you are going to make someone gay he is a good character to do it. Someone we see at work, but would never really see his private life, other then occasional references, just as we don't see Archie's private life or Hodges...
On a completely different tract, if there ever was another LV/Miami crossover, like to see Bobby and Calliegh meet up? I could just see them geek about guns and who's collection is bigger. :devil: