That's beside the point: the idea of hedging your bets has its place. You already sink 8 hours every day into one company, it makes sense to invest parts or all your compensation into other things instead of dumping it all into the same company. Unless you are balls-to-the-wall bullish on this one business.

Perhaps talldatethrow believes that his employer sucks as a business, because they are overpaying workers?

Or when I was working for Google in the mid-2010, I thought Google was a great company and I liked working there; but I also thought that their stocks were probably overpriced. (These days, I guess Tesla or Nvidia might fill that role for some? These are just examples, I have no opinion on them.)

In the other direction, one can love Amazon as both a customer and a shareholder, while simultaneously not wanting to work there.

Not everyone has that luxury

That ignores the costs (time spent) of finding another company and assumes one has information to conclude that it does indeed suck less without actually having the experience of working there to know.

Ultimately I don't decide what company I work for, but others do

Countless reasons. Office is near my home, and maybe Im not hiring material at those better companies. But I might be bright enough to see that they are doing better than my company.