Talking to someone about a topic you specifically say you don't enjoy talking about only for the hopes that they'll give you freebies isn't nice, it's actually pretty shitty. Like you view the purpose of a social interaction as a gamble to win a prize. Mind you, if you didn't make such a fuss about hating the process of small talk, I wouldn't think that, but because you say it's something you don't want to be engaging in, I don't see how else to view what you're saying as some strange transactional thing instead of human to human connection.

And no, I don't refuse to speak to cashiers. If they talk to me, I answer. If there's something I actually want to say, then I say it. I follow blue collar workers around my house so I can learn about what they're doing because I'm curious. Don't frame this as some sort of elitist snobbery when all I said was that if you don't want to talk to someone about something that you either shouldn't talk at all or choose a different topic you actually want to talk about.