They call hiring people who live in lower cost of living areas of the US "rural sourcing". That's half the reason to hire remote workers, they are cheaper. Also with rural sourcing, the time zones are more compatible than outsourcing to a foreign country and its easier to arrange occasional onsite face to face meetings.
As far as companies not wanting to hire remote workers for senior level positions, I found it hard to find any senior developer/architect contracting positions that paid well in my local market. All of the companies that wanted my skill set at my price wanted permanent employees. I was going to contract this time around but I ended up takinng a perm position.
One big reason for remote work was so that companies could stop paying big bucks for commercial real estate, which requires big money and long term commitment. But some and now many more seem to be going the extra mile and hire from outside of the major metropolitan areas. That way instead of just saving on real estate, they save on salary too.
As far as companies not wanting to hire remote workers for senior level positions, I found it hard to find any senior developer/architect contracting positions that paid well in my local market. All of the companies that wanted my skill set at my price wanted permanent employees. I was going to contract this time around but I ended up takinng a perm position.