GPL and RMS is not anti-capitalist, Linus Torvalds and Red Hat for example made lots of money.
So you can have Proprietary license <GPL <BSD and you have dudes that love both proprietary and BSD and hate GPL, my only conclusion that this dudes would like to grab others BSD work and make it proprietary and make tons of money, this is not capitalism ; this is the toxic "How to make XXX$ in 1 month(10 steps) people.
let me explain, I see people selling this idea of you buy this cheap crap from China then do a small change , sell the shit and make tons of money with almost no work(I seen other get rich schems too, with books or other stuff). I think some GPL haters would love to grab GPL stuff, put their cheap shit on top and sell it and make tons of money. GPL allows you to make money though, you have to share code though so others could make money too.
P.S. I would really like to understand why GPL is anti capitalist or communist in some people mind, is it some FUD or some wrong usage of the notions.