It's actually surprisingly fun. My girlfriend spends like 10 minutes drawing these elaborate pictures for strangers.
The only thing that infuriates me is when people know what it is but can't spell the word and then give up.
I get annoyed when the "hard" word ends up being some rapper/celebrity name instead of something that everyone knows.
I've seen some hilarious Lil' Wayne & Tebow drawings though! Much more fun to me, but you're right, this is a world wide game.
I've never played this (first time I've heard of it), but it sounds like a game I used to play about 5 years ago online with people on IRC/Kongregate chat. I used to love it and spend hours playing it. Boy do I feel dumb now not remembering it when the mobile app craze started!