I think intellectuals are so anti-capitalist generally because they see an issue with society... such as poverty, for example. The intellectual then goes about thinking about how getting rid of poverty could be done. Once he has his 'solution', he needs to impliment (force it on everyone else) his 'solution'. The result is anti-capitalist. Capitalism, to me, is a socioeconomic system in which private property rights are generally the rule and are respected. But the problem is that the solution the intellectual dreams up (something like welfare for example), requires resources to accomplish. The intellectual doesn't have money that he can just give to the poor to alleviate poverty, so he needs to find a source of money (the government). The result is a foaming-at-the-mouth leftist screaming about how we need to raise taxes on the rich and give it to the poor, and that capitalism is the root of all evil, because it and the concepts that support it (property rights) stand in his/her way.
Note: the concept of property rights does not prevent the intellectual from achieving his goals. It only prevents the intellectual from achieving his goals with -=someone elses' money=-. In essence, in a capitalist system, these intellectuals are free to go out and create wealth, and contribute it to private charity if they please. Capitalism and property rights do not prevent these activities. They only prevent forcing someone else to do these activities for the intellectual.