The socket itself didn't fall apart, it only fell out of the fixture. (only snaps in place). The house (8 appartments + finished attic, built in 1914) belongs half to my dad, half to my uncle, my uncle does all the paperwork and is in charge of the repairs. As it is almost impossible maintaining a rental building without throwing in much of your own money your only chance is to take what you get. Furthermore, hardware stores rarely ever sell quality stuff, and buying at an electrician's is much more expensive. Hence the cheap fixtures.
Our metal sockets don't have that evil cardboard. Old ones just have more space between screwshell and outer shell and a porcelaine ring that goes betwen screwshell and outer shel seperating it and covering the exposed part of the bulb's thread. Newer ones just have an outer base contact instead of the large screwshell, and the thread holding the bulb sits on a porcelaine base in the outer shell. Thus these sockets are almost everlasting, just consisting of porcelaine and metal.
Maybe I can take pictures of the old fixtures, but it'll take some time, as I don't have a digital camera.
One of them still loked like new, the other one had a broken screwshell, missing shade and some other missing parts.