I totally agree with you. I have given up on reading some of the literary journal articles and those on some literary sites for just that reason. Is there a solution to the bias? I doubt it.
Literature is often geared towards social commentary. There's been a lot of political upheaval lately, and a lot of it is centered around the US. Comes with the territory of being one of the most influential nations in the world. Writers want to express their opinions about it through literature.
American literary magazines have almost always been political. Literary magazines are not only there to provide reviews, but to explain in depth the context within which literature is birthed and brought to fruition. Even if the publications themselves try to remain out of the arena, like the Paris Review, the people behind them are still humans with political ideals and beliefs that influence the direction of their work.
[Here's the table of contents from a 1963 issue of NYRB.](http://www.nybooks.com/issues/1963/02/01/
[The Paris Review actually explained its turn towards more explicit political writing in this article.](https://www.theparisreview.org/blog/2017/06/13/politics-and-the-paris-review-announcing-our-summer-issue/
I think what you're seeing is the effect of a particularly divisive moment in American political history making its way into the general zeitgeist, where it was once only the concern of wonks and conspiracy theorists. People are spooked.
With regards to the America-centric reporting, I think that has to do with many of these periodicals being American.
I agree with your observation, but unfortunately I don't have a solution to offer. (Sometimes I feel as if all reviewers and bloggers were taught the same formula of a tie-in lede about contemporary politics or pop culture, however forced and tangential, just to hook the reader--as if they couldn't trust that readers of a literary periodical had sufficient interest in books for their own sake.) Outside the United States, can you recommend any literary periodicals that don't keep injecting politics, preferably ones that focus on English-language books?
They are all like that. It isn't so much the focus on politics as the focus is always the same, only one point of view allowed or you are banished. There is no escape, and that's how the left likes it.