I think that bitcoin will never become mainstream due to the nature of it. The only possibility I can see that it will get mainstream is via centralized parties, like easy-to-use exchanges managing the users coins.
I think the best way of doing something is to find out about them before talking jack Robinson, bitcoin is what it is now and will never be changed or altered, don't even think of bringing in the idea of centralizing an already decentralized digital currency, even in cryptocurrency, we have to understand how bitcoin is more of being decentralized than many of the other altcoins being centralized.
When we are to also consider it from the aspect of being used as the mainstream currency, bitcoin can achieve this success without undergoing through any centralized proceedings, those that are very used to this digital currency could relate how and why.