Skimming the article, it fails to mention that journals have some power to assess systematic reviewer biases based on their past history. If reviewers are systematically are more permissive towards specific people's work, then good science is not their objective.

So, essentially it can be viewed as a diversity problem in the reviewer space. The journals have important responsibility on this and they can not present as neutral observers of this phenomenon where they say : "oh every peer reviewing has problems " and blame reviewers ethos that they are choosing.