Yeah makes sense, the US immigration backlog problem for us may never be resolved it seems. One of my reasons for moving as well.I know a few who have done that too. They pretty much treated it as a backup in case they couldn't get their H1B+i140 done in the US in time (Masters graduates can work for 3 years post graduation on OPT ... so that's 3 h1b lottery attempts).
I also know a few who moved to Canada for permanency, path towards first world citizenship and freedom from visa restrictions. Among my acquaintances, I would say that it's a 50-50 split.