Why are women composers still disregarded?

Did you know that throughout the 19th century and well into the 20th it was considered a ‘biological impossibility’ for women to sustain the kind of abstract thought required for serious musical composition? Or that in the 1910s women in London could be compelled to sit separately from men in concert halls, sometimes even denied entry if not in academic dress? How about the fact that the Halle Orchestra summarily dismissed all its female members in 1920? Or that from 1952 to 1962 only eight works by women were performed at the Proms? For a bonus point, can you name...