With cameras of course lack of backwards compatibility means breaking compatiblity with existing lenses. A complete "pro" set of lenses is worth thousands if no

With cameras of course lack of backwards compatibility means breaking compatiblity with existing lenses. A complete "pro" set of lenses is worth thousands if not tens of thousands. So this is a step to be taken carefully. When Canon retired the FD system, a lot of people were unhappy, certainly hurting Canons business at that time (incidentally, that caused me to swith from Canon FD to Nikon F when getting my first AF-SLR). In the long time, that big step has paid off for Canon.