The fact of the matter is that most alts out there are merely a vehicle to more BTC and hence more fiat, at least to these "investor" types. Hell, look at how Ethereum has been deflating the BTC ecosystem with it's IPO fund cashouts.

Since there is nothing keeping people in most alts since they are driven by pure speculation, they create negative feedback loops. For example, you notice the price of your alt falling, perhaps dramatically (since a consortium is leaving the coin). Even if you have faith in the coin, you may cash out to "buy back later," exacerbating the price decline. Even worse is, when price/volume doesn't return to the coin and people just continue to dump or leave coins at sell orders, clogging the order books with sell orders, traders are unlikely to return.

High PoS, almost by design, recognizes these aspects and creates an ethical pump and dump cycle. Minters are attracted to the high PoS; they stake and "trickle" a portion of earnings onto exchanges. Buyers are attracted to high PoS as well, but the sell side is so thin they have to either eat into it for big blocks, trade OTC, or provide liquidity on the buy side. Coins are kept off exchanges to mint coins, and any movement to an exchange requires (1) more work than just clicking sell and (2) a decision made in relation to the stake age - "Hmmmm, I have another 6 hours on this block, maybe I'll just wait." It's also clear it attracts a different mindset, since high PoS coins with a good community are surprisingly resilient.