That's a bit like assuming anyone who's been to Uni should consider teaching in the subject offered: a particular skill doesn't automatically extrapolate to a particular profession and why should it? I did French and I neither teach nor use French professionally...
I did say that it would be an option for some, not all. But I think most would find it possible to get work, even if not related to their sport.
As I've said, though, I have no problem with them doing reality TV and see nothing reprehensible in it. It's all very well criticising "media whores" but people enjoy these programmes and they wouldn't exist without those willing to appear on them.