It’s such a strange thing to bury ashes or consider them unique, all that makes us human or different have been burned away and all that remains are anonymous minerals that could be from anyone.
It's a human thing. After all, when you look at other people through the lens of pure science, they're all just collections of atoms, just as anonymous as ashes. Personhood is an idea - atoms don't care about it, whether they're part of a live person or their remains. Whatever symbolism we attach to human remains is not really any different.
Agreed, I never understood all the weirdness around human remains. A lot of the rituals stem from ancient practices aimed at reducing the spread of disease - either that or religious beliefs.
I always tell people that I want a Tibetan sky burial - chop me up and spread me on top of a mountain to be eaten by the birds. At least they'll get a good meal out of it. ;)