I think that two years is a little bold. It will take more years than that for mass adoption. It still has to break free from all the negativity from the early years. Then people have to trust it more than gold and cold hard cash and that won't be easy to come by, at least not straight away. I feel even 5-7 years may be needed. Regardless, we are still early adopters.
He's not saying mass adoption will happen in two years. He's saying give it two years for it to get rolling. I think if you look at how fast technology moves and all the money going into bitcoin tech and start ups 2 years is a fair speculation, though I agree it'll likely take around 5 or so to make its way further into the mainstream.