It generally takes less effort to emulate ancient software than to bring ancient FOSS back to life. Sure, the emulator is FOSS, but that's fitting in the 80/20 rule just fine. There's plenty of broken, abandoned and dead FOSS emulators, too.
Sure, but I'd have a tough time finding proprietary software that I'd want to use that isn't adequately emulated. As for updating, well, I'm not going to be updating most FOSS, either.
Right now I can double-click an icon on my desktop that launches SimCity for Windows 3.1 inside of dosbox, and it works great. It didn't take much effort to get working, either.
I can't say the same for most dead FOSS that I've tried to resurrect. Usually I'll have to manage the outdated dependencies somehow, perhaps by writing a SHIM or somesuch; and probably significantly fiddle with the build system because Linux systems have changed significantly since the mid-90s.
It's a difference of hours versus days of effort. I've done both, but guess which I simply _haven't the time for_ now? I've got family and friends that need my attention moreso than a dead piece of FOSS no one but myself seems to care about.
Not quite, there are ways. The Diablo mod community is an excellent example: before the debug symbols were found on the psx release, the common method was to inject instructions directly into the binary. Similarly, Fallout and the Infinity engine games have mods that patch binaries and replace DLLs.
Yes, that's right, certainly easier than having the source. Your friends and family must appreciate the time you saved them by injecting DLLS. You'd better hope you efforts don't get DMCA'd.
Summarizing, closed source projects die. At best you can run them in an elaborate museum (emulator) and at worse, you can attempt to Frankenstein's monster them by injecting DLLs.