My issue with political economists, from a cultural studies and media studies standpoint, is the reductionist way of looking at it. It's not necessarily Marxist-based ideologies I have a problem with (I'm a supporter of Hall's British cultural studies model which is a neo-Marxist outlook) but rather the idea that society and culture, which are essentially defined by the struggle to control meaning, can be stripped down to a single economic determinant. It's just as bad as the traditional Marxist idea that an unassailable "Truth" exists and can be extracted by the move to a proletarian society. It's not so much an objection of methodology than one of principle or philosophy. I know economics are a major player in the movements of media producers, but at the same time I think the creation of meaning from media texts, on an individual scale, has considerably more determinants than market factors and financial antecedents alone.