Hmm... I agree with that Qur'an is kinda obscure when it comes to some verses like this one, that's why we have some opposing opinions regarding that matter from many major religious authorities.
But anyway the word "Hijab", which was mentioned in Quran, is actually a generic word in Arabic; it means something that covers/hides & not specifically a piece of cloth over the head, however some people may interpret it as a scarf to cover the hair, and others may interpret it as any other piece of cloth that covers a body's parts that weren't meant to be seen.
I believe it's not wrong to not cover one's hair, & wearing Hijab/Burka shouldn't be obligatory by law, as I find wearing them is more of a personal choice; if you find people always looking at your hair & you don't want them to then wear Hijab, if you have a physical deformation in your face & don't want to be noticed then wear Nikab/Burka...etc
And if your hair falls/gets deteriorated by wearing Hijab then don't wear it, I think God made that verse obscure like that so that Muslims aren't restricted to a certain outfit & Islam wasn't supposed to be too restrictive like that...
What do you think?