No, they don't want matching hobbies. Insert an alternate hobby below as needed
Mechanic time is actually masked alone time
Mechanic time is actually masked bro time
They're insecure bad mechanics
They're insecure good mechanics
They're worried the woman won't find her natural calling being a housewife and might brush off those duties to the man if he can't fulfill his mechanical duties
They're worried the woman won't be dependent on them for "very difficult" work that's also somehow super "easy for him"
They might have to intellectually debate the woman on a topic instead of just being able to coldly fuck her
I find this general mindset mad that modern mechanics are just "parts replacers" while they themselves also only replace parts. Yeah, the OEMs have spent decades troubleshooting and detailing repairs to make an entire encyclopedia of fixing the cause so you don't have to.