@ottocrat @davidallengreen Yes, commentary within a character limit. And very often context for a joke that might otherwise be somewhat obscure.
But there's no denying that QTs are responsible for a lot of whipped up conflict. One of the very first rules I adopted at the Birdsite was that anyone QTing me instead of replying wasn't likely interested in an exchange of ideas. I feel their absence, but it would be an exaggeration to say I mourn it.