Any PoS coin can be easily copied by others, so no big money will invest on it. Currently, with the huge hash power, only BTC cannot be copied overnight. That's the reason why most fund are invested on BTC related business.
It's not necessary to have a huge hashrate, because huge hashrate just isn't necessary when the main security threats lie in somewhere else. It's like having iron bars on your windows while your front door is still secured by linen cloth.
Most of the BTC related businesses aren't only BTC related. They are related to cryptocurrencies in general, because most of these companies can offer the same services while quickly adopting new innovating cryptos. The owners of these companies and their investors know that the future is in the field of cryptocurrencies in general and this (r)evolution won't end with bitcoin.