Well I've had far longer (and actual completed) RP's when I've GM'd them. So there's that. 

The times the GM was the primary reason it stopped altogether (versus other players/outside drama) [i]especially on this site[/i] is probably a 20 to 1 ratio. 

Usually the first time after one of the other players fail to follow a rule, or show that they failed to read information in a prior post. And the GM will become hyper-fixated on it, and end up spiraling down after. Versus punishing the culprit in-game/IC and moving right along.(Mistakes happen. Don't let it spoil the whole RP.)

[b][i]That[/i][/b], or the GM is ironically the very first to drop their own creation. (Effectively wasting the other players time.)

But both can be equally entertaining (or miserable) depending on the group/individuals you've decided to roleplay with.