Why stop there, why not include PPC, PPC64, SPARC, SPARC64, SH, ARM, and MIPS too? After all, since you're thinking of distributing source code, what is the difference? This resembles Windows not at all since Windows executables don't and can't work in DOS beyond printing a cheerful error message. Linux will recognize an executable is for the wrong architecture and refuse to run it too...

Your idea is essentially the linux distro Gentoo, which can compile the same programs on most architectures you've heard of and quite a few almost nobody's heard of.

Or, if you didn't actually mean source code, its more like OSX's "fat binary" system where they can include PPC and x86 code into one executable that'll work on both. This works well on OSX, since Apple has complete and total control over that system's foundation and architectures, but Linux is a little too anarchaic for this to work gracefully. There's more than two platforms, for starters; 'fat binaries' are already more than double the size of their originals, imagine bloating them to eight or 15 times that size. Then multiply that by all the incompatible distros and library variations and program configurations floating around. I suppose you could build one distro around that idea; considering most distros these days have 32-bit and 64-bit versions, I'm not sure of the advantage. That's a very business-oriented mindset to think we ought to care what platform you use. You playing halflife neither picks my pocket nor breaks my bones and certainly doesn't hurt the linux community. And it's pretty silly to try and 'threaten' us into using your idea before you find out whether it even makes sense. Nor was it ever similar to windows, it's much closer to UNIX things that already exist than it ever was to Windows.