Because some people who are in the right place and at the right time and who work extremely hard and make smart moves can become inordinately wealthy? This makes life not worth living for you?
Don't forget that to the 2 billion people who live on about dollar a day, your material life is paradise and your wealth equally as appalling.
Ha... Want to get more depressed? Alexa reports that Instagram is ranked as the 6,534th most popular site on the Internet. Compete.com said it had 331,529 users last month. Seriously, what the heck? What kind of reality distortion field did they have to come up with to convince the Facebook guys that this was worth $1 billion dollars?