It's rather pointless to talk about the greater population of users when considering whether a programming technology is pertinent. Sure, non-technical users don't use pipes. They also don't do any programming, and are completely apathetic regarding which programs they use outside of a few "core" ones like office or photoshop. In a word, whether Bob next door uses pipes or not is immaterial.
I'm sure this topic is dead, but just so you know, kernel debugging for windows uses named pipes at least when VMware is involved. .NET added support for named pipes in release 3.5. Mac OS X seems to fully support pipes, too. I suspect pipes are used, but transparently by most programs that use them.
