To me the issue surrrounding Keith Vaz is simple. Has he broken the law or the rules of Parliament? There has been no suggestion that he has. The newspapers who set up grubby little sting operations to expose people who have contravened nothing apart from a rather Victorian set of moral values fail their readers. I am sure the papers are well aware of plenty of politicians who are up to no good, who if they chose to they could do us all a favour and expose, removing serious crooks from public life.
I suspect Vaz has been marked out for payback due to some of the investigations of his committee. Whether or not his nocturnal habits are to your taste or not is irrelevant. We don't require politicians to state their preferred form of sexual encounter on the ballot paper or in their manifesto. Long may this stay the case.