No: the discobot is running. Even on this meta site, if you click the Chat and try to send a message “@discobot start tutorial” nothing happens.
I see what happened on one site (which I don’t administer): It has a “Personal chat” which appears below “Messages”, and I tried to use that by mistake. When you click on + in Personal chat you get a box that says “#a-channel, @somboy or anything” where I tried to type @discobot start tutorial. This failed because it is a search box.
It does work to type “@discobot start tutorial” in a topic, but then it seems like you are starting a tutorial in the middle of that topic, which is probably not what I want.
The verbiage in various places implies that I should be able to use @discobot anywhere and it will work… but this does not seem to work in the Chat for example. I ran through with a few other users to see what they would do to try and find help, and – even after I told them about the discobot tutorials, it was painful watching them try to start the discobot.
Similar issues are discussed in New users aren't starting the discobot tutorial - #32 by Dax.
Thanks for the help: I at least know now what to tell people to do. (I still think that an appropriate help button somewhere would be useful.)