I'm all for people wearing helmets.
Agree with the original post about setting an example and think about how the children could be effected if something happened.
And also I've lost count of the amount of times I've seen / been in close calls with cyclists.
Going straight through red lights
Riding two abreast (correct term?) on fast,busy, winding roads
Joining roads without stopping at junctions
It's scary people even considering getting on a bike without a helmet
I had one person a few month back who I came very close to.
I checked my mirrors, signalled, started to over take, and the cyclist just suddenly pulled hard to the right.
He was about to miss his turning and so He didn't check over his shoulder before moving to see if I was there. If it wasn't for the fact that I always leave plenty of room when over taking he would have smacked right into the front left side of my car.
He had no helmet