No just a few 'vocal' ones on here are saying no.
It's gone on since decks with pitch control were invented, and it will go on long after Denbo, Mark and the others are dust... it's part of the art of DJing, just like knowing when to and not to use the microphone.
Depriving someone of hearing a great tune just because it needs a slight tweak is IMHO worse than 'fooling' Denbo with the speed a track runs at on his Gramophone.
Just playing Devils advocate of course...