Salary is priced by the market, and that requires regular testing. Saying you don't want to hire regular job-changers is saying you don't want a functioning market. That, of course, is just what one would expect from companies who don't want to pay people what they are worth. Talk of 'loyalty' is effectively propaganda.
I've been asked for loyalty from companies many more times than I've ever been shown any. It's pretty rare that a company really sticks by their employees.
For the younger generations, after watching their parents work 20+ years at the same organization and receive a cheap watch, they have no illusions about who will be providing the loyalty and who will be receiving it.
"Loyalty" is staying together and providing work or benefits even when it is financially a bad move. I've never in my life seen a company that is loyal to its employees.
Even not firing people in recession times, providing four monitors or free massages and lunches are not loyalty if they make workers more productive or attract better talent. It would be loyalty only when these actions cost the company much more than they benefit it, as a gift to the employees out of sheer good will.
Part of a comment I left on the HN thread discussing Suster's post was "It was most often used when a builder had materials or a little cash available to avoid laying off good workers when there wasn't a contract job available." About builders building houses on-spec to keep together their core workers.
I have actually seen that happen, although it was at a factory, not some white collar place(where the watch would be better). A man worked there for 20 years and the owner gave him a $40 watch. He certainly earned only slightly more than minimum wage those 2 decades—more than the co-workers he himself oversaw. It was quite surreal, and unfortunately the meaning of it was lost on most present. I quit that job not long after.
There is a vast, quasi-invisible economic divide in America between rural and urban. Perhaps it's always been this way.