I would call switching POVs an advanced technique useable by those who know what they're doing, which is the same opinion I hold about present-tense, 3rd-person omniscient, and a number of other things that new writers try and fail at. Fan fiction as a whole tends to be very basic, transparent writing--easy to read, easy to write, but sometimes a little bland (most genre writing also falls into this category). One of the things I love about book-verse LOTR writing is the ability to stretch a little without being called on it.