In general, the wider the field, the more reviewing has to perform service functions: you the writer are doing the reader the service sorting through the pile of shit to find the notable things worthy of comment. So music reviews must be more service-oriented, in this sense, and film reviews, where a general interest in any reader can be more confidently assumed, have more leeway to be critical or to interpret or recontextualize. In film, where everyone is aware of major studio product, and the product is on such a different scale than independent productions, everything they put out gets reviewed, and a wide range of approaches are applied. In music, a small fraction is reviewed, even in music-only publications, meaning that the customary approach is to try to salvage what is worth saving, unless it's product from someone who's already famous.
So does industry consolidation allow for more thorough and engaged reviewing, since the concentration of releases means that reviewers won't have to perform the awareness-raising service? Should reviewers welcome the death of independent cultural outlets? Then they could rely on the core cultural competency that would allow them to take on bigger issues, bigger ideas then "Have you heard of this? It's cool." That, anyway, is the basis of the "Cultural Literacy" argument; conservatives who pedal it basically approve of authoritarianism and centralized control of taste, whether it is administered by the State, the academy, or studio execs and A&R men. But when such people control what culture is distributed, at least criticism often takes up an adversarial role more commonly and more explicitly -- "What is this shit?" and "Why don't we do better?" With a more wide-open distribution network, critics/reviewers get it in their heads to be tastemakers themselves, and they become the dictators. The only safe route for critics is to temper their practice with some rigorous self-criticism, as the hard-line Marxists would prescribe. What function is my criticism performing? What ae my aims, both spoken and unspoken? Who else am I serving by serving myself? What am I revealing and what am I hiding about the perspective I've adopted. If some of this self-analysis makes it into one's reviews, so much the better -- not unlike articulate how one is perceiving, like I was going on about yesterday.