The stereotype that women are worse drivers feeds in to unfair bias against and discrimination of women. Any “pro-man” statement also implies “anti-woman” unfortunately, due to the historical mistreatment of women.

Honestly, if you had said “Leos (or whatever) are born drivers” or “Great drivers run in my family” I doubt anyone would have taken offense. Both of those statement are also exclusionary of others, but not specifically women, so they’re less offensive to people.