We do not need to take this slow. We are not stupid. Insinuating that we are is not going to win you any arguments.Lets take this really slow. Sony had the only mirrorless FF option available in the market for years. Mirrorless market share grew for years. That means more people started using sony cameras right? If more people started using sony mirrorless cameras, do you think they still used old DSLRs? What happens to the market share when customers use company A's products more than Company B's? Does company A's market share grow or Company B's? I'm not sure if I am explaining this slow enough for you guys but trying to get to the point that sony has been making gains for years when canon and nikon had no mirrorless offering. They lost a crap load of customers. Long time canon users switched to sony in mass.
We understand that while Sony was the only one offering mirrorless FF, this means that some Canon and Nikon users started to buy Sony. We understand that while Sony continued to offer mirrorless FF and Nikon and Canon still had not entered this market, Sony continued making gains.
This is all fairly clear and had you stopped there, I don't think any one would have argued.
But you didn't. Assuming "a crap load" is a large number, well, you have presented no evidence and sales numbers from various sources seem to indicate that, no, Canon never did lose "a crap load" of customers. (P.S. Buying a Sony does not mean that Canon users did not keep their Canons or did not buy a new Canon camera as well as their Sony).
And, again, saying that long time Canon users switched to Sony "in mass" is not only incorrect linguistically, but also not true based on sales numbers. The phrase, by the way, is "en masse."
The question I am puzzled by is, why do people care if Sony or Canon sells more cameras? And why do people continually use these over-exaggerations when discussing Sony sales and their impact on reducing Canon sales? Even if every single wedding photogapher or every single wildlife photographer switched to Sony, why do you care?