You can buy stocks with no expectation they will increase in value (or even maintain value) if the dividend yield is high enough. And stocks have value because of this - the assumption in any stock, even one currently without a dividend, is that eventually it will pay out some form of a dividend to its holders.
You may buy a stock hoping it will will rise in value, but that rise is predicated on the eventual delivery of cash via dividends or some other mechanism of distribution. Contrast that with say, Gold, where in fact it costs money to hold and there's no expectation it will ever generate any kind of dividend.