In all honesty, Bitcoin is not yet ready for mass adoption. Don't get me wrong, minimal fees are great. However, this feature is overshadowed by all the hoops and obstacles companies have to go through to deal in Bitcoin, as well as the lack of fraud protection and overall user friendliness.
Why is it not ready? And there doesn't seem to be any hoops or obstacles. All they need to do is accept it which is simple to integrate whether you're an online store or brick and mortar shop. Fraud protection will be covered by a payment processor too, not that they have to worry about that much unlike credit card companies.
It is still an alpha software. Bitcoin Core is still alpha and hasn't even reached version 1.0 yet.