You misunderstand. The analogy wouldn't be Napster with networking code disabled. The analogy is Napster on a LAN. Only those on the LAN can access it so it's not open to the world, but nonetheless you've still got a p2p file-sharing client.

And yes. I'm using the engineering definition. I don't believe in letting a gaggle of marketers and scammers define my terms. A blockchain is a specific technology. It doesn't mean 'whatever scam is happening this week', even if said scam involves a blockchain.

I don't blame you for associating blockchains with scams and fully open projects, that's undeniably what we've seen it used for. But that's not what defines a blockchain.

"A scalpel can only be used for surgery"

"If you use a scalpel to cut a steak, it's still a scalpel."

"There must be some new aspect to scalpels! We've been able to make steak knives for decades!"

On reflection I was incorrect to mention Napster, which (at least in its most-popular incarnation) was still centralized for indexing and searching, with P2P only for bulk file data. Please pretend said "Gnutella" alone.

> The analogy is [the P2P application] on a LAN.

The analogy is the P2P application where regular clients can only discover a Special Master Client that must be running on a fixed IP, which only permits connections if you have credentials for a user-account arranged in advance.

In each case, the system's centerpiece feature is being voided, but that feature is different between them.

1. For "Blockchain", the centerpiece is unrestricted participation. (Other decentralization is an indirect effect.)

2. For P2P file sharing, the centerpiece is how nobody needs to run an expensive/vulnerable central server, but it wasn't a contradiction in terms to have a private peer-network.