That sounds like a very considered opinion, can you elucidate?
For the record, we've implemented IPP as CGI (well, a set of C++ functions
called by our general purpose embedded web server) and all seems to be
running fine. I can think of many reasons why you'd want to base it on an
existing web server, not the least of which is keeping the code size
reasonable. I would imagine that most printer OEMs would do a lot of soul
searching before deciding to use two separate instances of much the same
code in a printer...