Dividends are not a great metric for valuation. There are companies that are operating at a loss but still pay a dividend. Dividends aren't the only way that companies can reward shareholders. Share buy backs tend to be more tax-efficient than dividends.

Outside of oil MPs or Real Estate REITs I'm having a hard time finding any company with a dividend >6%

I will say I agree with your overall thesis that investments should be some function of expected future cash flows