I think for a long time now, there have been more people with money and ideas than engineers who can build them. I don't think this status has changed much in the last few years.
^ This is likely a large component - hiring in foreign workers who will need visa support is a lot of effort and money. You may need to have a niche skill that cannot be found locally, for hiring you to be worth the additional expense over a local candidate.
Not true, I have personally witnessed candidates being rejected for senior (engineering, not management) positions due only to lack of college degree. Obviously idiotic, but it does happen.