[CameronNemo]

It is not just this. It is also that RHEL 6 will have libfoo4, while Ubuntu 14.04 will have libfoo6, and then Debian Wheezy will have libfoo5. Even if the way the packages dependencies were expressed (libfoo-1-3 vs. libfoo3) were the same, the constant ABI breakage would be harmful.

[digi_owl]

But that problem is largely because of what i started out with, that their package managers can't handle having multiple version of libfoo installed under the same package name. Even tough ld and friends can via soname.

So they "avoid" it by insisting on using a specific version for the duration of the distro version.