I would never get a tattoo because I don't like the idea of something permanent on my body that I couldn't change, at least without a huge amount of pain to remove it. This doesn't make me think other people shouldn't have them, it's just how I feel about my own body.
Women generally know what suits them according to their body shape with regard to clothes. So your wife may admire something on another woman but know from personal experience it won't suit her own shape.