[quote=Captain Jordan]
This is the main reason I don't like 1x1s. If someone flakes out, the game is done. At least with group RPs, if one goes, there's a better chance of the story staying together. Even if it's the GM that goes, if the story is fun and others want to continue, there's a chance it won't die.
[/quote]

I'll second this. It's the reason why I'm rarely comfortable doing 1x1's.

I've done group RP's long enough to know that drop-outs are just a part of the game. They're pretty much inevitable. But, experience has left me fairly confident in my ability to work around player absences and keep the story moving, so long as there are still enough players remaining to run an RP. But with a 1x1, you can't do that. You're relying entirely on one person whom you've presumably just met and whose RPing styles and habits you don't know yet. The whole thing just feels... unstable, to me. Like a jenga tower supported by only a single block on the bottom row. 

In a group RP, there's almost always one person who has to drop out right when the IC starts. But at least all your hard work doesn't go to waste because of them.