The market demanding it would be Yelp being unable to hire CSRs in SF at their current wages and being forced to raise wages to attract talent.

That's one scenario, but there are others.

If enough consumers decide to stop doing business with a company because of the company's behavior, then that's also a kind of market demand. The article gives one example of such a customer, though it's unwise to extrapolate too much from a single data point.

Yes, but ultimately it goes back to being unable to hire at current wages. Let's say that consumers stopped doing business with Yelp and they did not raise wages as a result. Yelp does not have a monopoly and someone would create a competing business and hire away their employees. Yelp would either be forced to raise wages or do without customer service/go out of business.

The market and the mob are two different things.