I would personally be surprised to find out that tattoo artists are the kind of thing that keeps women away from science. I mean, it's probably a rare interaction. Blaming their parents seems more productive.
as an extreme comparison, if it was a woman dominated field and they commonly wore shirts depicting scantily clad men with bulging pants, I think it would impact my desire to enter that field.
I don't know that the parents can be blamed so readily. Here in Los Angeles at least, I've been very dissaspointed with what my classmates consider appropriate.
Feminism is not about being precious, it's about equality (which shirts have very little to do with).
It was a hand-made gift from a friend. He did it to make her smile. In such circumstances I'd probably do the same thing.