Oh c'mon dude! Just because of the transaction fees you cannot buy coffee? Even there is an increase in the transaction fees they are still low and will only cost you a few penny. Why blame the transaction fees? It is there to help the wallet provider to survive.
In my opinion, they blame the fees because of a very simple reason- they sent transactions usually, with small amounts of bitcoins in them, so it is very harmful.
When you own 1 bitcoin, and you make 0.02 or even 0.01 transactions, this 30-50k satoshi fee doesnt hurts you like that, an experienced bitcoin user knows many way to decrease the fee, or to regain the money spend on it somehow, without big effort.
I cannot grasp why would anyone think that the bitcoin has been made to pay for the coffee?
Blockchain is a great technology and bitcoin is also revolutionary, and paying for coffee with it seems like a stupid idea for me, you better pay with BTC for some electronical devices, or anything more expensive than 5$ lol.