We have canines for the same reason gorillas and hippos do. Probably because our ancestors used them to eat raw meat off of carcasses.
Personally the most use my canines get is when I'm chomping bits out of apples.
Seriously - If we filed down your canines would it have any effect at all on your diet? Do you really need canines to eat burgers, chicken drumsticks or even steaks? That we cook our meat makes our canine teeth pretty superfluous to our ability to eat meat.
So what is your point here?
You have canines....therefore what?