If I am writing an HTTP server then I do indeed expect "HTTP stuff" to "leak" into my source code.
There's no reason to assign methodology or context to a software process. It's useful or it is not, for qualities of utility that are unique to use cases. With such soft terms as "adapter" and "business logic" you can rationalize anything anyway, so I'm not sure that's a compelling statement on it's face. Across various languages, this methodology has been used since the 90s. It's "an oldie but goodie".
[1]"should" is a weasel word, that typically is a stand-in for "I believe this". It's unlikely that I subscribe to your specific belief.
It doesn't seem like they we're writing an HTTP Service.