The point of WSGI is not to be a good abstraction of HTTP. As an app author, you aren't supposed to care. The advantage of WSGI is that it's standard, and everything uses it. That means you can use any web framework with any web server, and it will all Just Work.
When you write your own copy of WSGI to change how some words are spelled, you don't gain much, but you lose the whole WSGI community. This seems rather pointless to me.
Take advantage of existing WSGI tools.
Pump comes with adapters for serving Pump apps with WSGI servers and converting WSGI middleware to Pump middleware.
When you write your own copy of WSGI to change how some words are spelled, you don't gain much, but you lose the whole WSGI community. This seems rather pointless to me.