It gives the media something to chat about during the interregnum of the run-up to a G.E. (bad timing, Andrew) when they have to be circumspect in their political reporting - a real gift to them. He was very unwise to bring it up when it had been festering quietly and could have died - but he isn't the brightest of the bunch.... not sure if that includes the dorgies or not.
The point at issue, so far as I can see, is not that he's an unsavoury person (which I, personally, think he is), but if he had sex with an underage girl. Well, she was underage in the USA - but not in UK and the incident everyone is on about occurred in the UK. Too much legalese for me, but I am certain that this girl was not a dewy-eyed innocent. No fan of Andrew's and totally fed-up that we've been landed with him as Duke of York. Anyway, that's why the media go on about it.