I don't know if I think "peeping laws" in general serve a compelling good. I prefer public toilets not be multi-purposed this particular way - but I'm open to the argument that there might be issues of autonomy or freedom that outweigh my discomfort. Having said that, whether or not the law Larry Craig is accused of breaking is just, or even whether, whatever that law actually is, it was applied correctly - all these seem to be side considerations. Whatever the case might be, I haven't heard the suggestion that Craig was targeted because of his identity or his job. There's no "unfairness" here, in that sense. And he isn't in trouble because of some summary offense (or misdemeanor, I don't know for sure) he pled to. He did something that was extraordinarily stupid, with full knowledge of what he had to lose. As a result of that stupidity, he revealed that he has behaved with blatant hypocrisy on important topics.
And then, whatever you think about any of the rest of this, he tried to intimidate the cop.