Not sure when it changes, but the usual explanation (by Americans themselves) of this US-only remote thing is that they afraid of dealing with the people who are not easily suable.
That's why you see food trucks offering tacos, sushi, or organic chocolate-and-truffle-oil-suffused hempseed brownies, respectively... but food trucks offering all 3 of these, not so often.
With recruiting it's kind of the same. Also, out-of-towners have different filtering / recommendation / communication needs, and take different payscales, also
So they're probably just applying the 80-20 rule, and catering to what their known client base seems to ask for most.