I agree. It seems to me that many use-cases for this technology fail on a typical Linux system because of the way software is normally distributed.
However, for multi-arch systems this might be useful, and I suppose that in the days when I had a mix of architectures it would have been nice to be able to install FatElf software to a shared network drive and have it just work. Plus for installers this sort of thing could be handy. But since most software that I install comes from a repository, a fat package would work just as well as fat binaries.