The old-timey socialist anarchists just don't "know the way the wind blows," apparently.  They want to freeze anarchism in 1880, and refuse to acknowlege the up and coming philosophies and movements.  In the words of Voltairine de Cleyre, advocate of anarchism without adjectives:

"there is nothing unanarchistic about any of them until the element of compulsion enters and obliges unwilling persons to remain in a community whose economic arrangements they do not agree to."