I can walk into my local café/bistro today and spend BTC instead of fiat... but - I'm not going to. It's a silly idea. The fiat I have in my pocket is losing its value constantly - in a month's time it'll buy me less coffee than it buys me now - so it makes sense to spend fiat, not BTC. (BTC is deflationary - in the long term I expect BTC to be worth much more than that coffee I could have bought with it).

Bitcoin does need to grow, the number of users does need to increase. But this "mass adoption" windmill is something we should stop tilting at. Bitcoin has far better potential than "something we can buy coffee/beer/groceries with".

I discovered Bitcoin shortly after returning from working abroad. I'd been paying a mortgage in one country while working in another. The forex costs were a killer (and I needed to plan ahead, since transfers between the two countries took a few days, and were a bit hit or miss in terms of time). This is Bitcoin's advantage for me - not a new way to buy stuff at Walmart.  That isn't to say this is the only use for Bitcoin, just that aping fiat is not a good use, and "mass adoption" (if it means granny can use BTC to buy her shopping) isn't a goal we should be seriously considering. (It is, however, one of those "truthy" goals, one that seems obvious and right - even if it's anything but).
 
(Disclaimer: I probably will use BTC in my local café at some point. But I'll do it to encourage a forward-looking business, not because it makes sense for me personally).