I must say, that i believe that bitcoin specifically is in a bubble. Its main asset is that it is a first comer, which isn't really enough to be the biggest coin, if you ask me.
So i do believe in a big correction at one point, like we saw with the .com bubble.
But like with the .com bubble, some companies will make it out alive, and grow huge (Amazon, apple, microsoft, google etc).
I think we will see the same with blockchain technology, as it grows and matures. Most coins will dissapear from existence, but some will stay.
I believe that steem is a remarkable good technnology, and if we do right, we can compete with the likes of youtube, facebook and twitter. And i can't wait until that day :)