The "there is no tech talent in Canada" folks have their heads buried in the sand. Markham is a tech hub, and so are a bunch of other places. Obviously it doesn't have the scale of the Bay Area, and the salaries are indeed lower than the Bay Area.

Many of us choose to live in Canada for a variety of reasons, and it is not because we couldn't get a job down south. Some of us even had to turn down moving to the US multiple times in our careers, but that idea is uncomfortable for some folks. It is almost as if some people value other things in addition to money.