Well, I don't play in any coverband or any tribute band or any band, but I don't see anything wrong in playing the music made by the band you like most and trying to do a cover just for your fun and the people who is watching you.
I suppose when you go to a "Whitesnake tribute gig" by your local band is because you like Whitesnake and you go to have some fun at your pub while drinking a few beers... Of course you'd like to be at a Whitesnake gig better, but they are not going to play in your local pub, so...
I think is a good way of having some fun and enjoy live music. I don't see the need of dressing like the Stones, anyway. (I agree with Stikkyfinger that it would be too embarrasing that your lead vocalist would be dressed as Mick on the 73 tour, for example. And more embarrasing even if he is 1,90 m tall and weighs about 90 kg. That would be shamefull, really
). But doing covers of your favourite band is OK for me.
[There'll be no wedding today...]