I havn't done much package maintenance myself but I've created the occasional Debian package. What I've noticed is that over the years the tools have gotten better, but one thing hasn't changed: developers do not know how to release software in a way that makes it easily to distribute.
This isn't surprising, it's not a course you can follow. You learn only by seeing how other people do it. Though the rise of alternative build systems like cmake en autotools have reduced the number of sharp corners.
In the beginning the debian/rules file was a makefile you made that described how to build the software, I guess similar to the Gentoo ebuild. Nowadays you have debhelper which has so much intelligence that it correctly guesses defaults for a large number of build systems and builds a decent package. The rules file can be almost empty.
My guess though is that much of the software that makes AV Linux special is of the kind where the quality of the build system is "a makefile that works for me", and turning those into decent packages is a *lot* of work.