Downplaying its importance because someone personally doesn't think it matters much, is .... what's the word?
Ignorant, self centered, dismissive... take your pick... there are lots of them. I know how much importance was placed on having properly plaited, uncut hair, for some of the more devout people in my circle of family and friends. I've seen how upset someone could get over something as simple as being seen with their hair undone, let alone how cutting it would upset them.