Whats holding us back is its TOO FKING HARD TO BUY!! 
This is also true. Coinbase is making a killing and I'm surprise as to no competitor yet, for U.S resident.
Kraken, no?
I heard about Kraken before but never look at them, also what I heard it's for Europe. I think people can't buy Bitcoin using bank account or credit card yet for U.S resident or perhaps I'm wrong as I never look at them.