You are deeply mistaken in thinking that share prices have no influence on value creation. Let me explain using your example.

Imagine that GOOG has a few projects in the pipeline. A few bad ones, and a few brilliant ones.

When GOOG share price is at 700, GOOG can issue 100 shares and raise 70000. Plenty of money to throw at good and bad projects.

If GOOG share price was at 200 they would raise less than 1/3 of the money, and be very picky at what projects to fund. Only the best project would get funded.

Think about how much resources are wasted in the society though misallocation of capital due to inflated asset prices. You may look at short sellers in a completely new light.