S/H pot depth

[sept2256]

it is a very interesting discussion. I had the same doubts. So, let me repeat if I have well understood.
In case os dry environment (like my house) It is better to use normal (shallow) pots. In case of right (hight) humidity, taller pots are preferable. But what happens if also in this second case I use shallow pots? I thnk nothing!! So why don't use only shallow pots in all cases?

Ray sad "Now I base pot choice on the root system and growth habit of the plant." Ray, what does it mean?
Thanks, Pierangelo