Just because merchants are accepting bitcoin doesn't mean people are going out and buying bitcoins to spend at said merchants. And guess what those merchants are doing a soon as they receive bitcoins as payment for goods and services?
Bingo
Any merchant who accepts Bitcoins needs to cash out
really fast. We're seeing 25% changes in a day, and 10% changes in 10 minutes. By the time a Bitcoin transaction is confirmed, it may have lost 10% of its value. You can't run a business on that.