When Proudhon, Bakunin and Kropotkin were writing the beginning writings that anarchism would grow to follow there was no acceptance of capitalism. Capitalism was not an option for anarchists. Anarcho-Capitalism is no within the scope of these philosophies nor is it anarchism by those original definitions. I have a laundry list of issues with Anarcho-Capitalism.
All of this aside, I realize once we have achieved some form of large scale functioning anarchism I do not believe these people will vanish with their ideas. The question is often asked if anarcho-capitalists are anarchists. My answer is yes. I know many will not like that. I do not see Anarcho-Capitalism as anarchism, but I will not deny one their claim to being an anarchist if that is how they define themselves.
I believe Anarcho-Capitalism clings to many forms of hierarchy and privileged and forms of rule that I reject. I also believe that we are all blind to the privilege we do hold, all of us, even myself. I do believe there are forms of hierarchy and privilege we all have that we can not see. I will not rule out other anarchists because they may have some beliefs or assumptions based in this unseen flaw therefore I will not rule the individual anarcho-capitalists out either.