I think you are missing the bigger picture here.
Those are not rules, those are guidelines that experienced people know will work with new owners to get them on track as easy and as fast as possible.
Does that mean you should not experiment when you have experience under your belt? NO
Do it mean people who provide those guidelines apply them to themselves? NO
I feed the evening of an arrival, I don't use a hot spot most of the year and I do many other things I would not recommend.
Why don't I recommend them to less experienced people? Because they probably would have issues and my goal here is to help new owners get started until they have sufficient knowledge and understanding of their animals.