Indeed, Canon will not care about some letter from a bunch of camera gear geeks like all of us here or elsewhere. Vote with you feet. I personally doubt that the 6D will sell very well. But I'm sure Canon has done their market research and have their reasons to believe that it is a good model for them to release as it is. Maybe it's just there to drive the sales of other models. I really don't know. There is not enough detail in their financial statements to fully figure it out - or at least I couldn't the last time I looked at their data -yes, I'm really geekish enough to actually do such a thing; I do, however, draw the line at specialized industry market research reports that you can buy for big chunks of money...
Canon (and very few others) has a fascinating business model in a very difficult environment that has dramatically changed over the last decade and a half. They have done many many things right and at the right time. The fact that they still exist is somewhat of a miracle and attests to the fact that their marketing folks are as savvy as their developers at least.
By the way: the next industry changing wave of disruptive innovation is well underway. And it may be more difficult for Canon and Nikon then the digital revolution. With the capabilities of iPhones and such the market for P&S cameras and even entry level DSLRs may shrink. That's a problem because for these companies that's where the money is - not counting Canon's "professional" (non-camera related) business line or Nikon's medical devices, etc.
So instead of whining and complaining about this, that and the other we should be glad that we still have options. I could see a future where professional grade cameras might be very expensive items for a small market segment. Think Leica's business model. This kind of stuff has happened in other sectors. I'm thinking of professional audio equipment for instance. While a lot of things have become digital and dirt cheap - and surprisingly good, other high grade pieces of gear have become very very expensive for those who need it or think they need it. Or try finding a real watch maker these days. Mechanical watches have become a pure luxury item and the handful of people who can service them charge an arm and a leg.
If we are moving into a direction where large(r) format SLRs or beyond become considered obsolete by the vast majority of users you are going to end up paying dearly to the few specialized manufactures who still make this for you.