Let's say that Craig was intending to do what has been suggested. And let's say the person in the stall next door was a receptive and willing participant. I assume that some sexual activity would have happened in one of the stalls there in the airport bathroom.
I know that if I were traveling, I would prefer not to encounter that in the course of my trip. And I do not think it is unreasonable for police to take steps to discourage that sort of behavior.
And as far as I understand it, the punishment for this "crime" was not unduly harsh. And in fact for most normal situations the whole encounter might well have simply been a slap on the wrist directed at encouraging people to find other more appropriate venues for their predilections.
If the person in the bathroom had been some known gay (Barney Frank for example) we would probably would not hear so very much about it. Didn't the severe punishment of this case result from public reaction to the exposure of Craig's hypocrisy?