The idea that the hoof holds onto or grows anything because it has a mindful preference for that thing has always baffled me. If we really believe that, why trim at all? If we believe that, every horse has exaclty the foot it wants, even the corkscrewed ones.
This false sole is there for a reason, for sure. But it’s not because the hoof or horse wants it there. It is there because this hoof has been trimmed in a way that created a situation where dead sole could not naturally slough off.
Hooves are devices that run on proprioceptive input and responses to ground forces. They are machines, of sorts, running on a program, and responding to their environments. They are programmed to grow and respond, at a biological level. They are not at all thinking structures with opinions. They run on input of information and output of growth. And their ability to run according to their programming can be hampered by how they are maintained by ground forces or humans. The more parallel the walls of a foot, the easier it is for dead sole to remain trapped and tamped solid by ground forces, especially as the wall grows beyond live sole, especially if the wall is heavy and strong or held tight by a shoe.