Writing is a skill that few people have really learnt to do well. For them, following some "random rules" will improve what they write.
Regarding writing 500 line functions in code: very occasionally you need that, but there's nothing wrong with an IDE that points it out and asks if it's really a good idea, and for new developers who would do that sort of thing all the damn time it'd be very useful in improving what they come up with.
Learn the rules first, then learn when they don't apply.