This is good from Martin Paul Eve. Reading his book on open access – here is the section where he talks about peer review.
The first point to note is that the gatekeeper model – that is, the system of deciding on permissibility before publication through both publisher policies and peer-review practice – works on a series of unspoken ideological assumptions that are never wholly objective and apolitical, but are rather, at the extreme end, based on a series of exclusions and marginalisations. While much review certainly is aimed at improving work and there are often substantial efforts to bring work up to standard through iterative commentary, at high-end journals and publishers there must be a percentage of rejections based on notions of importance in order to match page budgets and preserve prestige. This is because a gatekeeper model sometimes pre-defines its audience and disregards a series of important questions.