You make a good point though, I've often wondered why they don't shout more random words rather than profanities.
I wonder if its almost a psychological filter removal where their true feelings/thoughts spill out.
I remember watching some programme a long time ago, where the girl said it was the things in the back of your mind that you know you shouldn't say. So if you saw an overweight person you'd think (consciously or subconsciously) about it but not say anything, whereas with Tourettes they focus so much on not saying anything that it comes out, if that makes sense?
It was so lovely to see what everyone had been up to, especially Richard. That man must go through a bottle of Lynx a day. I wish that horrible girl had been on from last year with the brittle bone disease who immediately shot her date down because he was in a wheelchair.