I could never justify the cost of a Keurig when a traditional coffee maker costs just 20% the price. After using a drip machine for many years I finally decided to brave a more unique solution, the Aeropress. Now I know what great coffee tastes like. I tried a Keurig equivalent recently and I can't believe how much worse it tastes. With a Keurig you pay a premium price for poor quality coffee.
For me, my Keurig is a combination of speed, convenience and utility. The coffee it makes is a method for caffeine delivery, not coffee enjoyment. On the weekends or when I have more time, I'll make a better cup of coffee. Monday morning when I'm trying to get to work, I'll grab a travel mug of Keurig.