I like to change things up a bit. If I don't feel like my keeping goatee, I can shave it off. If I don't feel like wearing tennis shoes, I can put on a pair of doc martens (a gift from an ex, I'd never make that type of purchase) loafers etc...
A tattoo is a permanent billboard on your person that you cannot shave off or take off. Personally, I'm not a fan of women that use heavy makeup, but at least they can wash it off. That can't be done with a tattoo. Even if a tattoo is removed, there's still a noticeable outline in that area.
While others may disagree (and that's okay) I view tattoos as a sign of conformity and/or an attention getting mechanism (neither of which, I find personally appealing). In addition to this being said, I just do not see them as "cool" or attractive.