I feel the reason for the low rate of adoption is just because people think it's not for them. Bitcoin has been around for over a decade, and any thought that most people would have had about it being a scam must have faded by now.
My take on this is that the word no longer says bitcoin as a scam, it is just a simple lack of interest. And this stems from the fact that people have not actually taken their time to understand what Bitcoin and the Bitcoin ecosystem is all about personally I believe that most people are just too lazy to do their own research. They would rather go with the public verdict than their own opinion. This has led to them not being able to buy Bitcoin, store Bitcoin and even make simple payments with Bitcoin.