agreed, that is annoying. I try to have methods for dealing with situations like that to minimise the annoyance and not alienate people by getting upset with them though I do admit that it’s difficult sometimes.
I’m sorry but I really don’t agree with this. There are lots of games that take more than 10 minutes to teach (an 18xx, a Mindclash title or many of Vital Lacerda’s games, for instance) and I think that putting an arbitrary time limit on yourself leads to stress, hurrying and a bad teach in the long run.
Better in my opinion to learn how to be engaging for the full length of time that teaching a game needs than to panic and think “oh no, I have to do this in 10 minutes otherwise everyone will switch off” and rush it.