...PoS systems have no capital requirements for security...
They do have capital requirements (stake needs to be purchased first just like ASICs need to be purchased), just not as wasteful as PoW systems (ASICs life is 6 months and then you need to upgrade to new ASICs, not to mention electricity fees, datacenter rent fees, etc. and all that at an increasingly wasteful rate to compete with other miners).
Inflatable PoS is wrong, no doubt about it. Any inflatable PoS crypto should be avoided. Luckily, there are uninflatable PoS crypto 2.0 technologies, which are not wasteful as PoW.
Stake isn't capital. You can base PoS on tokens like travel points. Capital is fixed value hardware or natural resources. Bulldozers, ASICS, oil, and licenses are examples of capital. PoS tokens are speculative vehicles that may or may not have value except as a security token like a Verisign cookie.