Adoption has been sluggish even though news of bitcoin has been mainstream for the past couple of years because most people don't trust it's chaotic value. Most merchants will not use a currency they have to constantly adjust the price to (also people in general aren't going to spend something that might double in value in a month). It is not widely used in commerce because bitcoin is not really a currency, but a commodity. People hold bitcoin just to make money. It has become mostly self-serving with only a few bitcoin related services scattered around the edge. There has not been much of an increase in adoption because it's just not really that useful.