Earlier quoted context omitted.
Six months to land the right job holds for any job or field, remote or not. There's a lot of jobs available, but along with that you need to be picky - it can take some time to find a competitive, ideal option.
Let's say you take 6 months to find the competitive, ideal option. And you get an extra $20K in salary, going from say $100K to $120K (remote). So you sacrificed $50K in opportunity cost. End of year 1: job A $100k, job B $60K End of year 2: job A $200k, job B $180K End of year 3: job A $300k, job B $300K Of course if it's a startup, the odds are high that it would fold within three years. So unless it's a BigCo job…
It's a problem because you end up with an employee who is now being paid below market rate. This is most effective against those who are not employed, but once they are employed they will be hearing from recruiters or start looking for the next job while still on the payroll. Because this company is unlikely to provide aggressive enough raises, their employees will be receptive to new offers. A year or two out, this employee gives 2 weeks notice. Was the win of saving the company a couple $10k worth it? Most likely not.
If employers have trouble both finding and retaining talent, then this is a mistake to leverage this against unemployed candidates. If you don't have this problem you soon will once recruiters discover a company full of underpaid but qualified candidates. People leaving is also a signal to current employees that better deals exist somewhere else.