We currently live under the misapprehension that a company growing from a value of $100 million to a value of $1 billion is a "productive use of capital". My contention is that in general that is not true, and that kind of growth from big to bigger is harmful. We want to disincentivize the concentration of growth and capital in already-large companies, and incentivize the diffusion of wealth in many small enterprises that never grow huge.

The very fact that a company grows in value from $X to $X * 1000 is proof that it’s productive use of capital.

You can say that, but then I can say why do we care about whether something is a productive use of capital? What I care about is life being good for human beings, not "productive use of capital".