If you think Snapchat has the same macroeconomic value to the world as Intel, Cisco, or McDonald's... Then you've lost the ability to evaluate a technology business.
I'm not sure whether to accuse this of being shill or to systematically prove how flaky the argument is. The fact is that it doesn't save photos is as much lack of a feature as it is character. The users of this app know how to take a screenshot... It's the ICQ of a different 3 years worth of teenagers that will get stomped by the next messaging app that is different from the one other people used for the past 3 years.
Snapchat is valuable because of demographics. Unfortunately those demographics grow up quickly, and the ones that replace them will rebelliously reject what preceded them just like teenagers have done for the last 50 years.
The fact that they are worth $18bn now is nothing but a prime example of the times. Mind you I know the company I'm in. VCs invest based on their bet and the reason that valuation sticks is more marketing than it is reality.
Snapchat just isn't that valuable to the world.