The requirements are generally clearly communicated. The strictness is about publishing quality science. Someone who has not been through the peer review proces

The requirements are generally clearly communicated. The strictness is about publishing quality science. Someone who has not been through the peer review process before might be quite shocked by the stringent requirements to get a paper published. Again, it is NOT arbitrary; it is about making sure the journal is publishing real science and not quackery. It is entirely possible for someone outside of academia to publish, but having guidance to get through the peer review process is invaluable.