Correct me if I'm wrong, but I believe most of the fish species that we as anglers target were introduced and not natural to this environment. They, just like carp, were introduced into our water systems.
I come from a European background, and carp are seen in the same league as trout, as far as freshwater fishing went. My father taught me how to fish, so I grew up with his respect for the fish and I was always baffled by people's disgust in carp. But they were fun to fight and were a challenge to consistently catch, so they remain one of my favorite fish to pursue.
Especially in Ontario, there is such a variety of water bodies, that we are spoiled by our choices as to which fish we are able to pursue. I have found that carp can coexist with a lot of other species and there are man other water bodies that do not have carp at all. I do not appreciate when people look down on other people for the fish they pursue- leave them be and let them fish. If you are curious why I enjoy fishing for a certain species, I will be more than happy to explain it to you.