You can, actually, and how close it is to the way php works is all to do with the fastcgi handler, and little to do with the language. Wsgi has configuration like WSGIScriptAlias, WSGIScriptAliasMatch, and WSGIScriptReloading that would make it almost exactly the same as default php behavior.

I suppose it may not run efficiently that way, but it would run. And you don't have the built-in html templating with php, where any html file is also a valid php file.