[psyc]

I'm struggling to pinpoint where you two are talking past each other. "Length" in the context of a blockchain refers quite specifically to the amount of actual work. So "easy" to make "long" chain, seems like a straightforward contradiction.

[KirinDave]

The amount of calculation necessary to add a block to the chain is not undoable by someone with modest resources.

What's difficult is doing it as quickly as Bitcoin miners with specialized hardware and big energy footprints.

You can make a new blockchain add got Bitcoin today on EC2 without overwhelming expense. Even 30 of them. No problem! It'd take too long to be practical for mining, but that's not the senario we are discussing

Would you beat other miners in? Absolutely not. But the scenario being discussed here is the historical value of blockchains once there is no mining pool racing on them.

And the answer both the article and I propose is: "It is almost none" compared to the other cryptographic tokens. Especially if the chain isn't receiving constant, small commits.