I was recently made aware of how petty, back-stabby, front-stabby, cliquish, in a word "political" the peer review process can be. I thought that peer-review was a rigorous, objective process, but no, it's just an "old boys" network once again.
I found that out while in medical residency and fellowship. 100% political. Has nothing to do with the validity of a study. It is why I left academic medicine.