As people move towards adopting the use of BTC and other cryptocurrencies especially in their everyday lives and routines (especially also if merchants begin to use blockchain projects and Altcoins in their payment processes), they'd be less resistant towards paying for simple purchases like coffee with BTC. Many projects are also have digital wallets that are linked to a debit card so that you can convert your cryptocurrencies and make purchases instantly on fiat terms at physical stores at little to no transaction costs and foreign exchange fees even, so buying a coffee using BTC or any other cryptocurrency may become more convenient than using fiat eventually!