I think you mean the opposite, given the phrasing of the question.
> They don't have huge PR VC teams behind them, hence you never hear about them.
This seems like half an argument. I get that PR teams have an incentive to talk about their company, which is why they are in the news sometimes. But it doesn't explain why non-VC backed companies that are swimming in cash would be so elusive. Would they be in the news? Perhaps not — though they might still want to generate PR for themselves, to grow their business.
But you'd think that people in the startup world, who spend lots of time reading about startup strategies, examples to follow, etc., would have heard of such companies if there were many out there. I've been at this for a number of years, and I rarely hear about bootstrapped startups that are quite so successful. I guess PE folks would have a good sense, since such businesses would presumably make great acquisition targets.
And perhaps that's what keeps them so rare — someone making a couple million a year would rather sell the whole thing for $20M and move onto their next thing (be it a startup or a private beach), and there are plenty of acquirers who are happy to make that trade.