~snip~
Can they even accept btc legally as a payment method in Bulgaria? If so, than at least it wasn’t for nothing completely.
Bulgaria is one of the EU members, and as far as I know, none of the EU members prohibits the use of Bitcoin as a currency, moreover, in some countries you can pay practically everything you want with BTC, and also some countries have 0% tax with some special conditions (if you sell BTC one or two years after purchase).
I can't say how good a business idea such a bar is, but I can agree with @Rikafip that it's not a good idea when it comes to the privacy of anyone visiting such places.
I don't see a problem with patronizing such businesses, except the person goes there and starts bragging about the million dollar worth of BTC in their hardware wallet at home, or if they pay with an address that stores majority of their funds running into hundreds of thousands or millions.
The privacy risk is the same as walking into any bar, everyone can tell you walked in, but they don't know what you own, except you give that info away. You can be robbed or traced back home right after coming out of a bar thar accepts only fiat. I feel if you do what's right and don't do too much, you can have a beer and pay with BTC without any problems.I would not agree that the risk of entering a Bitcoin cafe is the same as a normal one, because I think it is much easier to
"convince" someone to hand you a piece of paper with a seed, than to rob their bank account. In addition, people go to such places to have fun and relax, and this includes drinking alcohol, maybe even drugs - and under such influences, people often say what they would not otherwise say.