My philosophy is that a bad night at the theater is pretty much better than most other nights. My philosophy is, if you're miserable and not enjoying yourself, then leave and do something you enjoy. I've sat through a lot of stuff over a long period of time and that includes terrible shows or productions where I stuck it out through the whole show. As a result, I know when I am miserable to the point where I simply do not want to waste any more of my time forcing myself to watch something I truly don't like. I can leave at intermission having gleaned enough from the production thus far to weigh the value of my time, energy and sanity against the production that is contributing to my unhappiness. If I were a critic and being paid to watch, I'd stay. If I have friends in the show, I'll stay and support them. If I paid for a ticket, I'll leave when I want (which in the case of a couple of excruciating shows could be 15-20 minutes after it starts).
In the case of Priscilla, I was actually coming down with some sort of flu or something during the first act, but honestly, had it captured my attention, I would have stayed. But I was actually really REALLY bored. And I've never felt the desire to go back and see the rest.
If you're an actor or a director or a set designer, isn't it interesting to think about the choices that were made vs. the ones you would have made? I don't have to force myself to stay to the end of a show I don't like to think about that. Usually, I leave because I already know what I hate about it. I'm just not a masochist. Well, not when it comes to theatre.
"What can you expect from a bunch of seitan worshippers?" - Reginald Tresilian