F stop for landscapes w/ em-5

Golly.

Whenever I read threads like this two things occur to me...

Firstly, why on earth does a landscape shot need front to back DoF? One of themost famous landscape shooters of all time came to realise that front to back DoF doesn't make an image look natural and wished that he could retake one of his most famous shots and give it limited DoF. I'll let anyone interested Google

Secondly, DoF tables and CoC and viewing a specific image size at a specific distance, is this how people view? I suspect most don't these days. What is wrong with shooting at different settings and seeing what works best for you (the shooter) and your style? Why should there be rules?