[Lazare]

> Nice try, but if the outer layer is UDP, then NAT alters the UDP packet headers. The QUIC payload is never touched.

You didn't understand the article. It's talking about existing TCP traffic here, not QUIC.

> I don't see why the people tasked with standardizing Internet protocols now have to make provisions for the jerks who literally break the Internet.

1) A lot of them are the same people and 2) internet protocols are worthless without adoption, which is why we're still groping towards IPv6.

Or for a shorter answer: Politics.

> How is this bit even useful for anything?

Here's an internet draft proposing adding a spin bit which discussed, among other things, some uses for it: https://tools.ietf.org/html/draft-trammell-quic-spin-01