Thinking only in black and white, a clear indicator for insufficient mental dynamic range
Where did he say that no professional commercial/fashion photographer used Canon?
I believe he said that, when they do use Canon, they have a problem which they would have liked to see fixed.
As for the fixing - does a sponsoring contract outweigh the costs of additional processing? That's why prominent names are ideal for such ideas, esp. when they use said gear only for selected jobs, not exclusively.
OTOH we just ha(ve/d) the fashion weeks and the related shoots - a much more representative cross-section in my book.