It's kind of cool, especially the fact that he's elderly. That generation is often too conservative and can't accept or understand new technologies, like cryptocurrencies. Wouldn't call it an adoption, though, but that's definitely something. All big steps are made up of small ones.
Also, I was surprised by what many said here. Is it really that risky to wear a BTC shirt? Can someone attack you just for a shirt? I thought robbers look at things altogether, e.g. if you walk out of your Rolls Royce in a shirt like that - sure, you're at risk, but if you're just an old, soberly dressed man taking a light walk in the morning, would you still be in danger because of the logo?