Yes. In fact, the whole architecture is designed for general-purpose request/response serving. It's just that the most common implementation of that particular paradigm is HTTP.
What you get from HttpServlet is additional functions that understand the specific needs of an HTTP server. If my memory is any good, among other things, that means that the raw Servlet's service() method is overridden and replaced with on that calls doGet() or doPost() depending on whether the incoming HTTP request is a GET or a POST.
Customer surveys are for companies who didn't pay proper attention to begin with.