Why does Pinterest need $400M in venture to operate? Lets ask ourselves why a glorified status feed, Twitter, needs over 100 engineers. Why does Twitter need to rewrite almost every aspect of real-time stream processing? Because there is huge value there, and at that scale I'm sure the financials look a lot different from your weekend web app.
Back to snapchat, this tech doomsday bubble, everyone is parrotting is a single lone horse in what are many successful and sustainable companies such as DropBox, Uber, RocketFuel and Square. And its not like snapchat is an imaginary app. Snapchat shares over 350M photos a day, people aren't lining up and seeing snapchat success overnight.
I'm having trouble seeing that the current tech industry is in a "bubble" when the only evidence for it is that SnapChat, with an incredibly huge userbase, is raising ~3B. For whatever reason the other 39 "unicorn" companies don't count.