I see this as two large market segments -- 'keep it small' and 'keep it seamless' that have relatively contradictory asks of Canon that speak to fundamentally different form factor camera lines w.r.t. the mount and lens ecosystem.
After that, sure -- we'll get wrapped around the axle about how they did / didn't...
- Automate the AFMA process
- Give us spot metering at any AF point
- Offer some kind of eye AF routine
- Give us a blackout free EVF
- Give us an SLR like control/button setup
...the way we wanted them to. That's going to happen.
But those things get sorted out in the next model or two without a huge impact to customer satisfaction, loyalty, etc. I see the mount decision as the huge fork in the road Canon will have to get right or potentially suffer for a long time:
- New mount and a less than perfect adapter or super tiny grip = angry customers who wanted a seamless EF experience, an identically handling second body to their primary FF SLR, etc.
- Keep the full EF mount and you horribly p--- off the 'keep it small' crowd, the folks who wanted to dabble with Nikon lenses, build small street/travel rigs, be more likely to carry a smaller rig around with them more of the time, etc.
Yes -- they certainly could end up doing both -- it's not like they're going to sign up for a dozen FF mirrorless lenses out of the gate. But the first body that comes out will all but certainly set the 'losing' party into a tantrum and send a small short-sighted/short-tempered portion of them to the exits.
- A