If they do produce enough to be worth $150,000, why pay them less just because they live in Wichita? Supply and demand, sure, but it just seems odd to me to explicitly say that you're paying less if someone lives outside of a major metropolitan area. I prefer to be (or think that I am) paid based on the value I produce (value pricing) rather than what it costs to keep a roof over my head (cost pricing). Whether or not this is the case also influences my understanding of how a company thinks about me.
salary - CoL/year = reward_dev
The CoL modification to the developer's salary has nothing to do with whether the company makes more or less revenue as a result of their work.
My guess is that as companies find good talent increasingly hard to find this problem will resolve itself as the remote workers outside major metropolitan areas get bidded to higher and higher salaries.