It is easier to write movie reviews or merchandise reviews than it is to write about new albums. I think this is down to feeling more empathy for struggling musicians than ultra-rich movie companies who are able to make films so expensive that their effects budgets alone could feed a country for a year. With film and TV I can be more vicious- I'm just another hack, and my bile or hyperbole won't really do much for their sales either way. Film reviews are so common and so varied that even the worst aberration will get a shining review somewhere, from either a madman or a studio plant.
With music, it is much more complicated, as my words do actually carry some weight. A great deal of the music I review for the magazine is from small labels and new acts, who are also facing the struggle of playing music in genres that are not currently massive sellers. Reviews of these releases can have a huge impact on sales, and do actually have some say in the success of the album.
Even if the music you're having to listen to is not of a genre you are particularly into, you cannot just dismiss it outright. You need to listen with an open mind and recognize that there is some talent at work. As well as the songs, you must take in the performances, the production, the mix, the presentation. Everything. Even if I am sent a promo by a band I have an abject dislike of, it will receive the same honest review it would get if I loved them. That's how things are. The knowledge that the 200 words or so that I bash out has the task of summing up months of work for these musicians is always hard to think about. It is also why it has to be really, really bad to get a negative review from me. Absolute honesty in writing reviews generally will help you find something positive in the most difficult of releases.
The point? Reviewing anything can have a great effect. Think of the work that went into what you are listening to/watching, and the effort that people made. You'll find it much harder to review things, but you'll also find that what you write is much clearer, much more informative, and much better.