People who want modern things don't buy turntables. So tradition prevails. If you don't like "Phono", get a CD player, or better yet, get an iPod. Frankly, calling them "turntables" is letting enough modernism into the whole thing, so youngsters like you ought to be satisfied. The player is a phonograph, and it is the platter on which you stick the record and its mechanism that is the turntable portion (the tonearm is not strictly part of the turntable, though people now use the word "turntable" to refer to the whole thing). A turntable is also used to turn trains around:
http://en.wikipedia.org/wiki/Turntable_(rail)
One could probably also call the mechanism that rotates a CD a turntable, which would lead to all sorts of confusion (
a turntable is simply a rotating platform). It is best to refer to the thing as a phonograph or gramophone (in reference to the British upstarts who came out with such a thing years after the Americans made phonographs, so if you like newfangled words, call it a "gramophone").