Why don't these pupils cycle to school?

A few days ago I spoke to 120 year 7 pupils at a local secondary school to promote a forthcoming Pedal Power Kennington 'Dr Bike' session there, with an optional after-school ride. Most of the pupils said they had bikes and there was enthusiasm for the events. I subsequently talked to a class from year 8. Letters were given to all 240 year 7 and 8 pupils to take home.

Yesterday I arrived with a mechanic at the school to undertake the Dr Bike on a warm autumnal day. There were 9 bikes, from the whole school, in the bike racks - how many might one find on a day with no cycling events?

Mind you, the school is a hundred yards or so from TfL's local collision centre, the Vauxhall Gyratory, and slap bang on the 'Berlin Wall', as Val Shawcross described Kennington Lane at Monday's Kennington Association AGM.
The Berlin Wall being the inner ring-road around the Congestion Zone from Vauxhall Gyratory to Elephant and Castle.

Photos like this demonstrate that the Mayor and TfL need to pull their respective fingers out to improve conditions for active travel, which is why I'll be on Blackfriars Bridge this evening at 6pm.