It would be nice to know what that bias might be. For example, "bias towards truth" is different than "bias towards restoring the US to British monarchy."
Mother Jones is of course a politically progressive magazine, so there's a bias in the topics they cover. But that sort of bias says nothing about the quality of the coverage. The Economist is also 'incredibly biased' in what it cover, and they do good job of it as well.
Similarly, Mother Jones wins awards, like the National Magazine Awards.
Quoting its co-editor Clara Jeffery http://www.wnyc.org/story/what-its-when-redditors-ban-your-w... :
> We report from all side of an issue. We do investigations into things that people on the left or the Democrats wish we wouldn’t. And all of our journalism is fact-checked, sourced, and linked through. Facts are what we do, and statistical data analysis journalism is a big part of what we do. So I don’t see that part either. And we don’t really lace our reporting with opinion. It’s more, we’re a shop that cares about the little guy and inequality. So that informs some, but by no means all, of our story selection.