I think it would be difficult to argue that it's useful primarily for buying your groceries.
I don't think Bitcoin advocates like following this train of thought any further than "USD is also used for crime".
My point is that this conversation is unfair:
Person A: I've just invented a new currency! I think it has better intrinsic properties than USD.
Person B: Well, I can't buy groceries with it right now, so it sucks.
Similar vein:
Person A: I've invented a new thing called the lightbulb. I think it will revolutionize lighting.
Person B: It's more expensive than oil lamps and electrifying buildings would be a massive undertaking. Lightbulbs suck.
As it was, they were primarily used for lighting rooms from the getgo.
I imagine some historian could probably dig up some sort of analog from 100+ years ago (possibly on tech that never did take off) but this isn't it.
I would like to buy groceries with it, but I don't want to hold much BTC for very long.