And yet even the most basic telephoto kit lenses in Canon's EF-S line exceed 200mm. An EF-M equivalent to the 75-300 would even be a quantum leap forward. Doesn't stop me from longing for, well, longer, of course. Hence my statement about imagining a tiny 100-400 equivalent. Doesn't make it any more likely. But still...
The M series cameras are capable of taking very good photos. I know that I'm not supposed to utter such blasphemy on the fan pages, but I ditched my old DSLR mainly because I found myself carrying my M3 a lot more often. But its an inarguable point that, in terms of lens selection, the M line is something of a bastard stepchild in Canon's lineup, as they've never really fully supported it beyond some very basic parameters.
And again but even more so.
In truth, Canon has given the entirety of the APS-C lineup the cold shoulder, and sold a bunch of cameras in spite of themselves. They've only produced 12 EF-S crop sensor-native lenses since 2003 (22 if you count multiple versions of the same lens), compared to 34 camera bodies. But they also had a good lineup of compact full-frame lenses to lean on as well. A great example would be the 75-300. I didn't realize until just now when I did some digging that they've never produced an EF-S equivalent. They were so common as the telephoto lens in twin lens kits for so long that I just expected that they were EF-S native.
I can't speak for everyone, but size certainly played into my decision to go solely with the M series. I am presently shooting mainly with an M50, which I have had GREAT success with. Most of the time, I shoot with my 16-35 f/2.8L, and try not to think too much about size. But there are times when size makes a difference for me. The EF-M lineup doesn't have a full frame infrastructure to fall back on beyond what's available in the EF lens lineup. And the size difference there is glaring. Canon COULD do more. And they haven't. Whether by laziness or (more likely) perceived lack of market, the end result is still the same.