The elephant in the room: consumers have almost no incentive to use bitcoin.
The common talking points are:
Low fees - The consumers pay no fees while using a credit card. They actually get rewards points back.
Privacy - As evidenced by a recent post, bitcoin offers little privacy out of the box. You need to go through hoops to achieve privacy. People who care enough to go through these hoops have better alternatives (like cash!), which are more foolproof.
Being your own bank - Few people want to take the risks associated with being a bank. It is more of a headache than a plus.
No consumer protection - No need to elaborate.
Distrust of the monetary policy - The volatility of bitcoin makes it useless as a store of value, and there are better and more reliable options to store your wealth. Few people buy into the tinfoil-hattery that the USD is about to crash.
There is simply no pragmatic answer to "Why should I buy bitcoin?"