RAT 5 to reply to your question first, yes VC Cockpit has some members flying to those airports , also in the turboprop category but this is not their mainstream membership base ,( i.e) LH Germanwings/Eurowings ) and to be fair to them , they have other priorities those last years
There are many such small airports in Germany (for instance in the South West : Hahn , Saarbuecken, Mimmingen, but also Ramstein AFB ( which has more traffic than Mimmingen or Saarbruecken combined ) All have a very small Class D CTR until around 3500ft and class E above until FL100.
Hahn has CTR until FL 65 and established a TMZ ( transponder mandatory Zone) all around its CTR but only until FL65 .So from 65 to 100 , class E
Those airports are mainly used by others EU airlines ,e.g Ryananair, Wizz, but also sometimes TUI fly , all 737s and A320s, Luxair for instance goes daily to Sarrbruecken with a Dash8 .
Main problem why it is (still) like this is the DAeC lobby .( Deutsche aeroclub) which I support for many other reasons but not on that one.. But we are touching the good old German " freedom" concept which was very good after the war but does not work too well with Safety in the XXIst century. . Same for the Highway speed limits . The Porshe BMW and Audi lobby year after year works hard to maintain free speed on motorways , and no-one serious in politics will try to change this , despite concrete evidence that extreme speed on the road is dangerous, kills and pollutes...
But this is Germany ...A country, like Switzerland, where Traditions are strong and more important than mere facts .. It has also a certain charm I must say...