I heard this junk over and over in seminary, and I never really bought that the story of Sodom and Gomorrah was about "hospitality" either.
If it were, where does God state in the salvation narrative up to that point that violation of hospitality is a sin so grave that he would destroy a city over it? One would think a commandment that grave would have been spelled out. In fact, I would argue just the opposite. God kicks Adam and Eve out of the garden (not a hospitable act.) God not accepting Cain's sacrifice was not hospitable. God commands Noah does not let anyone into the ark after the flood starts (not a hospitable act). God gave no such commandment, so therefore if he did destroy Sodom and Gomorrah over violation of hospitality, he is most unjust indeed.
Just because Bedouin culture today has a central place for offering hospitality, it does not mean that was the way it was way back in the times of Genesis. That was a completely different world with a completely different worldview. Tribes are and have always been very hostile of outsiders. Just look at how the ISIS is kicking out, murdering, and raping all the Christians in Iraq right now. Hospitality is not even the code of desert in that same area today.
Just because you might feel like this story might hurt the feelings of the homosexual crowd does not give you warrant to change the text. Making the text say something it clearly does is anachronistic at best and does violence to the text at worst. I don't buy it, just like virtually everything else I heard at seminary.