I can't say I remember what the actual "backtalk" was, but I frequently got in trouble for my tone (as opposed to something like telling them to go fuck themselves, which I wouldn't do as punishment was often physical). while my tone did frequently veer toward having a 'tude, which I'll totally cop to, it was also used as a reason to punish me for the content of my words; they SAID I could say whatever so long as I said it politely, but in practice they'd either accuse me of having an attitude where one did not exist, or intentionally goad me into an argument until I did get an attitude and punish for it. every conversation was a minefield. children are to be seen and not heard, and shouldn't speak unless spoken to, etc.
adults loved me when I was a kid, and I used to be proud of that, but I realize now it's because they terrorized me into being nothing. I recognize it when I get agitated with my nieces for just, like, being kids.