It's a bit extreme to conclude that since Node's built-in HTTP server works this way, that it's "cancer." People still use it because it suits their purposes; there's nothing wrong with that.
AFAIK, nothing's stopping anyone from writing a CGI module for Node. It took years for Python to come up with WSGI and Ruby to come up with Rack. People are fed up with CGI and I don't blame Node's developers for excluding it.