And it's an unbelievable pain in the ass when they change packaging styles, and the new src packages aren't compatible with the older build tools. IIRC, that happened between 10.04 and 12.04.
It did, but it's only relevant for packages which actually updated their build scripts. A huge proportion of packages from 12.04 will still build fine on 10.04 (which I've been doing in order to backport certain packages to install).
