Why not? If they're teaching her their values, that's a critical aspect of parenting. (Arguably, the most important aspect.) My mother tried hard to teach me her values, with only partial success. It didn't take. I mean, I disagree with at least 70% of what my mother values, and believe about a quarter of it to be actively evil. But she tried really hard to raise me with those values, both in the sense of making me grow up surrounded by them, and in the sense of wanting me to grow up having them. The bar mitzvah circuit was a significant part of that.

Where I come from, bnai mitzvah parties are *supposed* to be a chance to show off wealth and status, and formalized sexual display. I've always been uncomfortable with that sort of thing, and I was even less comfortable with it when I was younger. Thus my reputation for being anti-social.