It's pretty funny actually, it exists because people are evil. Let me explain this a bit more in-depth. All of us humans are untrustworthy, we all have this darkness inside us, if we are forced, even the most "good natured" person can steal,kill and whatnot. Why do people keep secrets? Because they did something bad. Why the need to lock our doors, keep our "data" safe? Because someone can steal it.
Bitcoin exists because encryption exists, and encryption exists because people were evil and didn't want their war plans to be discovered by the enemy. Get it so far?
Everytime I hear new encryption was discovered, I giggle a bit, because the reason they make encryption/ciphers is because one the first chance they get, humans will compromise some data.
That's a kinda dark view on humanity, isn't it?
But, well, you have a point. But, then, I guess most things can be traced back to selfish purposes if we want to?