I don’t think we’re arguing over strawmen. You seem to think one should not mention it if they get the wrong drink order, regardless of how politely they bring it up. I think it’s ok to do so, provided it’s done politely. I’m not trying to argue that point, mostly just offering my opinion. I’m not suggesting the customer is always right, just that it’s possible for staff to be wrong and it’s not improper to ask them to fix a mistake. I understand that in the OP the guy is wrong, but that doesn’t mean everyone should just take what they are given and be happy with it regardless.

I’m may be a dirty commie, but I think capitalism has really messed up the way people perceive people on the other side of exchanges. Baristas are often overworked and underpaid but that’s not the fault of the customers who are often also overworked and underpaid. If someone decides to spend some of their limited resources on a treat for themselves then I think it’s ok that they make sure to get the thing they asked and paid for. I am personally boycotting a lot of big brands, but I’m sure local places are also taking advantage of their workers, there’s just no big campaign against them. There’s no ethical consumption under capitalism etc etc, but we all participate in the economy and should care about how others are treated. If I do something wrong I want to fix it because I care about you and your experience. What you want matters to me and you should get it. You should also care if that affects me and my day and should try to minimize the stress by being polite and understanding. That’s my overall thought process.