Beware of slogans. They are verbal camouflage for weak arguments. None of these arguments have withstood close scrutiny, but at least they were offered in the spirit of honest debate. Such arguments, even though deeply flawed, never infuriate me. Opponents of laissez faire love this one because it so obviously describes an economic system that no reasonable person endorses.
Capitalism is internally and inexorably fettered.
To the extent that a society is capitalistic, no one in that society can coercively or fraudulently harm others. Everyone is restrained from violating the equal rights of others. He earned an impressive fortune by producing affordable computers that consumers voluntarily purchase. Like everyone in a capitalist system, Dell was and remains quite constrained by the rules of private property. Had he produced lousy machines, or had he stubbornly priced his machines so high that too few consumers bought them, he would today be in some less-lucrative line of work.