> (a) let anyone in and you get a** and total dilution of cultural values (quick death of the institution)

The counterargument to your point is somewhat self-evident: all the great nightclubs in Berlin that have way more relaxed entrances than Berghain that aren't filled with assholes and aren't completely diluted of cultural values.

Often times it's the exclusivity that attracts the assholes who normally don't listen to that kind of music anyway.