Player cancelling aren't that of a big deal comparing to GM cancelling. In the first case you keep playing while shit talking about Bob, in the other, you have to change your plan for the evening
That seems unfair to the players who were ready and excited to play. If i set aside 4 hours to drive to a friend's house and play games, and im told it's canceled because 1 person said they can't show up, I'm gonna be pissed.
I assume when people say "cancelling" they mean "I'm on holiday next week so can't play, sorry". Barring emergencies, who would be so rude as to cancel at such short notice?
This is making planning ever more complicated, I try to have 4 or 5 player, so the game can run with 1 or even two player not showing. Sure if someone just don't show on a regular basis, I'll re open her place to a new player. But people are abroad for work, have to deal with their kids, or have a peak of work, they let us know, and we find an in game reason for their character so not be available and the game runs fine.
Even when the GM miss, we all have ready to play one shots lying on our computers, so not that of a big deal
We have the policy that we play as long as no more than one player cancels and their character is considered to never have existed for that session (important story items are of course transferred to a present character). Works quite well.
I tried to push for more practical approach to playing without a single player, but both in my D&D and in my Blades in the Dark groups, players just feel...uncomfortable with the idea and don't want to play if all players aren't there. I once proposed a system where we could play in smaller groups to accomodate one player's schedule not matching others...and upon realizing they wouldn't be playing in full squad in this sytem, that player just quit the campaign.
Nope. I would never, ever do a thing like that. I've certainly never sat at my computer drinking beers and complaining about people changing plans at the last second.