Converting PostScript to anything else is rather hard. To
see why you should stop thinking of a PostScript file as a
document but instead think of it as a programming language
which is capable of giving a printing device instructions
that will cause it to print out the document.
Yes, if you send a PostScript printer the correct document
rather than printing it will instead install a stealth
backdoor that contacts someone and tells them that their
latest victim is waiting. I forget whether the default
password on HP printers was "OOOO" or "OOOOOO", but it is
fairly simple to guess. And, as you can imagine, most
people don't realize that their printer is a fairly capable
reprogrammable computer, with an operating system (written
in PostScript), full networking capabilities, etc.