Oh, I don't know ... if you're going to do something, why stop halfway through?
Topic on Category talk:Examples Need Sorting
I don't think anyone will consider it a bad thing to alphabetize it, but most people don't care on trope pages, so the alphabetization probably won't once the page gets a few new entries. Also it probably discourages people from adding the category to virtually every trope page they see, which would make the category almost meaningless and inhibiting the notice of those willing to organize a trope examples into sections (by media of course)