If you use them in CGI mode, you very well have a "start" tag in form of a shebang first line like #!/usr/bin/env python.

Also, shellscripts and perl are considered programming languages, and these too need a shebang line. Your point is invalid.

Well, many Ruby webapps use erb, which is basically the same thing.

With PHP, unlike other languages, you have not two but three options - you can either run it as a web server module (That's your "templating" opinion and the most common use of PHP), you can run it trough the Common Gateway Interface (where even in Python or Ruby print DOES outputs to the HTTP) and in the end you can roll out your own HTTP server. In the last option, just like the common use of Python and Ruby, you have full control of what's going on with your code and you decide what to send over the socket and what (if anything) to print on the console.