what's value of linux being modular

What's value of linux being modular if it needs so many duplicate and different versions of the same libraries.

I am running debian squeeze which has almost 50% packages from wheezy such as xorg stuff, kernel, drm, mesa and some application software. However, accidentally I found that I've bewildering number of duplicate libraries. It's insane, can't even remove those duplicates as they are  dependencies for a variety of packages. In the normal world a later package should override an older version, but it's different in linux, sadly. Even if I've deborphan and debfoster I see tons of different versions of libraries such as: libavcodec, libavdevice, libavfilter, libavformat, libavutils, libdb, libjpeg, liblzma, libmatroska, libnspr, libntfs, libssl, libswscale, libusb and libx264. Please have a look at the youtube video to know what I mean.