Why do you consider them part of the "regressive left"? Is it because you think they've behaved unethically, or are they hopelessly biased, or do you just disagree with them, or some other reason?
First, I looked up the term "regressive left" and you might want to know your use of the term doesn't match its general usage, which might make it confusing.
Secondly, I think you're doing yourself a disservice if you dismiss these voices and are critical of them but not the mainstream pro-Democrat press. Ryan Taibbi, for example, clearly dislikes Trump, but also thinks the Democrats aren't responding to him well[1], which is an interesting perspective to understand if you are anti-Trump. If you are a liberal who fails to incorporate or understand even the criticisms of people who are close to being your allies, you may be less equipped to properly combat Trumpism.
Basically, it sounds to me like you are advocating ignoring these people because you disagree with them, which doesn't strike me as the best way to rigorously improve one's political perspective.
That's why they are all appearing on right wing media, a shared enemy.