...And how grossly overpriced most of Canon's EF-S and EF lenses really are.
Or a lack of understanding of lens design by people with that opinion... Small image circle + less retro focus in the design because of the shorter flange distance means a cheaper lens (the latter is why the EF 50/1.8 is so much cheaper than the EF 35/2).
If they wanted, Canon could sell M-pancakes at prices very similar to the ultra-compact FF-capable EF 40/2.8 pancake - with excellent IQ and "good enough for me" build quality - and still make tons of money.
And for € 399 they could just as well have built an EF-M 11-22 IS with a constant f/4 aperture. All the difference would have been a slightly larger front element and a 62 filter thread instead of 55.
But lets wait what image quality the 11-22 will really deliver. And as long as there is no adequately performing EOS-M body, I am not interested anyways.
If they wanted, Canon could sell the EF 600mm f/4L IS II at prices very similar to the ultra-compact FF-capable EF 40/2.8 pancake. Or they could sell actual pancakes made from batter for thousands of dollars. If they wanted. Whatever. They're going to charge what they think the market will bear, and if you don't like the price, don't buy it. Oh wait you're not interested, so why do you even care?