Remember kids... always wear a helmet. (The almighty bikeradar helmet thread)

I have it on good authority that hand gliding is more dangerous than horse riding. HMmmm...we need some sort of flow chart here:

Hand gliding > Horse riding > cycling > walking > standing still > sitting down > lying down > sleeping > already being dead

Said in jest I know, but why would helmets not be compulsory for hand gliding and is there even a debate on it.
Why keep going with a debate on cycling helmets when the number of deaths doesn't even warrant a debate to start with.