Interesting, I've never made that connection. Not an easy fix though I think; taxing increase in market cap, through mark-to-market has its own issues.
That's what some of the proposals to tax "unrealized" capital gains try to do, but I don't see how it wouldn't be a huge mess.
I had an economics professor who rather eloquently made the case that we should just make it a legal and fiduciary responsibility of corporations to return money to shareholders - either as dividends or buybacks. They get taxed when the profits are realized, and they can always re-invest their (taxed) earnings right back into the company if they want to.
