I don’t think people really know what “derailing” means.
- How is somebody “derailing” by sending a message that nobody else has to see, and which nobody has to respond to?
- How is somebody “derailing” by reblogging a post with the addition of their own commentary, commentary which doesn’t have to be reblogged by anyone else?
- How is somebody “derailing” by leaving a comment on a post which nobody has to pay any mind?
Derailing is something that happens in real-life conversations, and also something that happens in web forums and blog comments where there is only a single conversation track (hence the notion of de-railing, i.e. a railcar being knocked off its tracks). But the structure of Tumblr doesn’t really allow for derailing to take place, without it being actively facilitated by the very person/people making the accusation.
So in summary, kids: on Tumblr, accusations of “derailing” are almost always unfounded.