So, back to the original question: what's the problem here? what is disallowed?
Also: If all pipes are files, but not all files are pipes, it would seems to me that files are more restrictive. That, and the extra steps you need to take to avoid needless IO.
that doesn't allow you to do all the things you can do with a real file
I'm not interested in what the differences between a pipe and a file are (I know) - I'm interested in why OP thinks they are relevant in this specific context/case; particularly in context of my statement:
seems to me that files are more restrictive
Is, for example, a sticky bit relevant to systemd log files?