It's been said a hundred times just what additional value Canon gives through reliability and the robustness of their products.
Some people are apparently too young to remember the EOS 1Ds III auto focus debacle right after introduction ... and Sigma's initial problems with OS in 120-400 and 150-500 ... or Metz's issues with exploding flash bulbs ...
Let's get real: getting a newly introduced product exposes you to inherent risks, and a proper recall is 1000x better and more honest than a company singing "lala, I can't hear you" to a torrent of problem reports.
What you say is true and understandable. But such things happen FAR less with Canon than with other manufacturer. Ya?
Since the 1D III AF disaster things have been better at Canon ... until now. Keep fingers crossed.
Nikon certainly has a QA problem. 4 out of their 6 recent FF DSLRs had a QA problem.
* D800 left side AF problem
* D600 oil splatter [not acknowledged - until mass litigation forced Nikon to step up to it; fix offered: D610
* D810 white spots [acknowledged, fixed]
* D750 flare problem [quickly acknowledged, fix offered]
see also Thom Hogan's blog: http://www.dslrbodies.com/newsviews/the-good-news-and-bad-news.html