Tattoo artists shave the location that your tattoo is going to be in for a couple of reasons : 1. It prevents the hair from getting caught in the tattoo gun (ouch!), 2. It makes it easier for the tattoo artist to see what he/she is doing, and 3. It prevents the tattoo needle from pushing the hair back down into your skin, causing ingrown hairs.
Whether or not the hair gets shaved has nothing to do with how the tattoo turns out. I have seen tattoos done both ways, with and without hair, and all have turned out ok.
