Share buy back programmes are equivalent to dividends in all but tax treatment. Why should the market capitalization / valuation of the company factor into a decision to pay out to shareholders?
Yes, but judging intrinsic value is something for investors to do. I want my companies to concentrate on what they are good at---and random companies are not good at playing the stock market. (See the other current discussion about Cooper Union (https://news.ycombinator.com/item?id=5599385).)
