You are absolutely right, and as many have pointed out these corrections are healthy for the growing market. If we look to examples from traditional and mature markets for example the corrections that occurred as result of the housing bubble 'burst' of 08. The markets than were boated with repackaged, triple A rated mortgaged backed securities which many knew were full of subprime mortgages (we could relate this to coins such as S**tCoin or Coinye West). Since these toxic assets were racking in billions of dollars a year for the banks and investors much like seen in our own ecosystem, it was only till a few negative events occurred like the bankruptcy of New Century (a mortage lender) where the downward spiral of the markets began, for us that was our Tether or Mt Gox moments. These crashes recreate a healthy ecosystem, and make worthless coins, worthless. We talk about store of value, however the only thing we could use to place as a value of the coin, is the work need to produce that coin. So in that, coins that rely on PoW should in theory have more value than PoS coins as they are more energy intensive. That is my two cents.
I find your analogy between the subprime mortgage crisis of 2008 and what happens in the cryptoverse quite appropriate and fitting. With that said, though, I can't agree that PoW coins should necessarily be more valuable than any other coins in existence today. I'm not very tech literate in this matter but I know for sure that the amount of labor put into creating something has little to nothing to do with its price, even purely theoretically. The price and value of an asset is determined by its utility and usefulness, not by amount of effort required to create or acquire it.