[arp242]

I suspect they intentionally break the HTTP spec for a similar reason: it will break some standard crawlers/bots, stop automatic retries, and things like that. This is trivial to account for of course, but it'll stop some script kiddies.

[ttymck]

They might also have desired it for "zero-cost" observability: everything already monitors HTTP status codes, so they can monitor bot traffic without custom instrumentation.