I usually get a little worked up with mechanical issues, but it doesn't last. If it's weather related, then I really know there's nothing to do. Everybody is fricked at that point.
You're right, there's nothing anyone can do about weather. And I much rather fix mechanical issues on the ground rather than something happening in the air and we have to come back or worse, divert.
The one thing that gets me is stupid mechanical things like a broken seat or some dumb arse kid flushed his shirt down the toilet.