Flaky people are the ones I hate the most. I find it very North American, in Italy if you say a thing it's gonna happen for sure, in North America it seems you can say whatever and it doesn't matter if it's happening or not it even you know it won't happen when you say it.
Socially, it's yes let's meet tomorrow, then sorry it's canceled or sorry something else came up.
You're so right about it being a North American thing, my parents were raised in Ireland and raised me with their ideals, but here, people flake out on plans all of the time. Doing that, you might as well say you think my time is garbage and you don't want to see me