Is minoxidil good to take for growing a beard?

No: It does slow the process of male pattern baldness. Several percent of men can't grow a good beard. Many women seem to prefer a smooth man. You don't see Justin Bieber or Larry Bird complaining. If you're "culture" disparages a thin-bearded man, you have my sympathy. Hit the gym hard, build yourself up, and nobody will criticize any aspect of your genetics.