Don't get how you find people who meets you on time "intolerant"
To clarify, I try to avoid people who believe that flaking or being a bit late is rude. Of course, I don't mind people who are on time.
What does 'flaking' mean to you? As in making something like a dinner plan and then just never turning up? I really can't understand finding that acceptable. Are you not annoyed at the waste of time and embarrassment?
Also, the wasted money spent on any travel costs, the wasted time spent earning the money that was pointlessly spent on said travel costs, and the opportunity cost of not doing something more productive with your time and money.
Loss of the cover to the restaurant as well. And you might not get a reservation there again.
Maybe I misunderstood the meaning of flaking as I'm not a native speaker. I would consider it rude if the plan was already under way (e.g. someone started cooking, already traveled to somewhere, etc.) but canceling plans a bit ahead of time is acceptable to me.
Intolerant of allowing people to waste your time or wasting other people's time?