Before anyone gets a tattoo, they should put a lot of thought and consideration into it. They're permanent; on your skin forever -- that should be a good enough reason alone, right?
Of course, if you don't like your tattoo you can always have it removed with a laser. However, the procedure may cost up to ten times more than what you paid for the actual tattoo. Also, it doesn't go away in just one session, it takes multiple sessions for it to be removed completely (black ink is the easiest to remove). It's also very painful.
Unfortunately, not everyone thinks ahead. These people are the ones with tattoos that are not only regrettable but make others want to cringe. All we can do now is hope they don't get any additional regrettable tattoos.