cherafel
Course, you could just use Visa gift cards for these kinds of usages. It's probably a bit more convenient to do it this way, rather than keep topping up a card.
Some other use cases noting that cryptocurrencies tend to have public ledgers.
Generally though, merchants wouldn't bother accepting it. Alongside the fees and whatnot, adoption is too low, fees are too high, time to confirm is too high, and it can complicate some legal stuff (like issuing VAT invoices).
Most cryptocurrency fans seem to be optimistic investors looking to join in on the massive returns seen by investors in 2016-2017. Most of them care more for generating 'hype' and seeing an increase in the value of the coin they hold, just so they can dump their holdings later. I don't think they'd be too interested in a coin that inflated in value that they didn't hold (they'd probably instead promote something they did hold). Most cryptocurrency fans do not hold one particular coin, and generally change which coin they advocate for pretty often.
Cryptocurrency communities are generally pretty toxic and non-constructive environments. I've been part of a couple, and I've noticed multiple times a massive decline in the quality of the community (and, sometimes, in development as well) as the cryptocurrency got more popular (and more people joined the community).