I believe his point was that Canon has designed the M system for size. No M lens has exceeded 61mm in diameter, which probably precludes any fast (>f/4.0) zooms. As dak723 alluded to above, if Canon wishes to compete in the higher end APS-C market, it will have to do it with the R mount. I believe that they will do so, but what do I know?Given, yes. But I don't think that my buying profile is shared by nobody else.
So there definitely is a market for faster glass in good build quality.
Not as big as the mediocre-performance-wide-zoom-range-plastic-mount
market, but certainly not irrelevant.