As I point out in my book The Lifetime Income Security Solution, dividends are a key component to investing. They lower overall volatility, steady performance and provide a constant stream of reinvestment income . The above chart partially explains why. Treasury yields started to drop in the early 1980s and have continued to plumb new lows since. While many people have correctly noted that yields have nowhere to go but up from their current position, it's doubtful we'll see a major advance with inflation so low. Add all this information together and you have a powerful argument for focusing on dividends.
You can read all about it in my book (shameless plug):