kdo

Jeremy Siegel's Silly P/E

Actually Siegel is right.
You say:

Earnings don't change according to market capitalization. The p/e ratio is an interesting animal: the numerator changes from day to day and even from second to second, while the denominator changes only once a quarter. It's an indicator of how the market (the numerator) is reacting to reality (the denominator). But under Siegel's method, the denominator changes every second as well. And rather than dividing the market by reality, we end up dividing the market by itself. Which is much less useful.

You're ownership of those earnings is changing with every individual wiggle of individual shares too. You just don't know it.