In the Age of Mirrorless, Do We Really Need APS-C DSLR Cameras?

The APS-C DSLR has been a gateway camera for many photographers, and some higher spec'd APS-C DSLR models are still used by professionals, and hobbyists alike due to their rugged bodies, and good overall performance, but with Canon choosing to kill of their sports and action centered EOS 7D models one has to wonder if APS-C DSLR models are coming to the end of the road. Should APS-C DSLRs still be produced by major manufacturers going forward, or should the switch to APS-C Mirrorless cameras jus...