"Why doesn't Farcaster have $0 sign ups"

Why doesn't Etheruem have $0 gas fees?

why pay for storage fees if the hubs are not being paid

Storage space is limited.

You don't pay node operators on Ethereum, either.

Working on Farcaster and Warpcast. Longer thoughts at https://dwr.email

You pay for gas that is then burned and the operators (stakers) get protocol emission, which is close to even or slightly deflationary. So you indirectly pay them. Also you tip the block proposer to prioritize the transaction. This is a sustainable model, how does farcaster compare here?

the grand majority of stakers are exchanges, this graph helps illustrate (some inside baseball: a good chunk of the "unidentified" is also exchanges), the remaining sizable percentage is via staking pools. Given only so many execution clients are needed to sustain this (since consensus clients are separate), it is easy to see that a significant majority of execution clients are used by people who are not doing so for earning purposes – why would they do this without emissions? because the data has external value

gm. Fulltime degen, building fun stuff onchain. 
Master of Disaster Frogworks, /ottodao bullfrog, ex @astaria