Tattoos are very much a fad right now, but for some people they are more than that. They are art and a form of expression. I would agree that generic tattoos are equivalent to guys with pierced left ears in the 90's, but there are plenty of custom designs that aren't. Tattoos also have significance in many cultures (historically speaking). Tattoos were very much a part of Celtic societies, and in Greece they were considered disgraceful--often criminals would be tattooed to signify them as such. Celtic tattoos could be a way of embracing one's heritage and culture, and Greek tattoos could be a way of rejecting social hierarchy. I think there are a number of reasons to get tattoos, some of which are pretty shallow, but many of which are not. Some people don't like tattoos, but others do. It is disrespectful to criticize what other people do with their own bodies, however, and I think generalizing people with tattoos is a bit prejudiced and narrow-minded.
Trying to express individuality or show non-conformity by copying others can seem counterintuitive, but really I think that most people who do so are trying to reject specific social standards while relating to people who share similar values. Expressing one's individuality (in a potentially non-conformist way in this case) is not only a matter of being different, it's a matter of associating with like-minded people. Thinking of non-conformity and individual expression as trying to not fit in at all is a misconception, much like people often confuse anti-social and a-social behavior. Not wanting to fit in at all would be a-social (schizoid/schizophrenic), and anti-social would be wanting to only fit in with a minority of like-minded people. I think a good example of this would be tattoo festivals, which show how people expressing themselves through anti-social behavior can associate. To be completely honest, one reason I want visible tattoos is to make myself more approachable to like-minded people, and less approachable to people who would judge me negatively because of tattoos. I also wouldn't mind covering up some scars.
As for tattoos in the workplace, things are changing. Lots of employers still discriminate, but an increasing number of them don't, showing a trend towards acceptance that is not slowing down. With how common tattoos are becoming in younger generations, and with these younger generations replacing the old, it seems like tattoos will only become more and more acceptable.