This sort of penny-wise, pound-foolish thinking is the root of the problem. Many large, important businesses start very small and stay small for a while. ( https://en.wikipedia.org/wiki/Microsoft#1972.E2.80.9384:_Fou... , https://en.wikipedia.org/wiki/Apple_Inc.#1976.E2.80.9384:_Fo... ) By admitting only founders of companies that are already large, you ensure that many of these companies are established and grow elsewhere.
> Why would the United States want to let you in where there are more promising businesses/entrepreneurs on the path to $100m/year companies within 5 years?
Blatant false dichotomy. Nothing prevents the US from admitting both.