If the intended audience is reading it, I would agree. However, many reviewers seem to be assigned and agree to review a topic that they are ill-equipped to understand without a substantial amount of background knowledge.

A good reviewer in this situation will review the referenced papers to bolster their understanding. A bad reviewer will expect everything to be spelled out within the manuscript, and, unfortunately, the length limits often don't permit that kind of write-up.

Precisely. The continued hyperspecialization of science shrinks the potential pool of qualified reviewers to zero. I rarely get knowledgeable reviews these days. Instead of disputing my methods, they complain about the font or figure styles, or raise questions that weren't answered in the paper because they are common knowledge in the field.

Peer review goes beyond simple issues about clarity or misunderstanding. In particular, peer review is sometimes seen as an adversarial process.

Often, the reviewer will not understand because he is not the intended audience. Other times, he will understand but he just doesn't like your method, because he is working in an opposite direction. Or maybe your method is a direct competitor of his and yours work better, which incentivizes some people to block your work.

Or your paper goes against the current paradigm or is otherwise politically unpalatable.

> Other times, he will understand but he just doesn't like your method, because he is working in an opposite direction. Or maybe your method is a direct competitor of his and yours work better, which incentivizes some people to block your work.

Oh you mean those phantom "off topic"/"out of scope" reviews.