"it can't compete with a Range Rover or Land Cruiser on the gruelling school run"
And that in a nut-shell is the problem.
4x4s have no place on the school run! Your little darlings will be just as safe in a "normal" car... In fact everyone else's kids would be safer if the view wasn't obscured by massively proportioned 4x4s parked up round the schools.
The Defender was a utilitarian work horse. It's not supposed to be cruising Chelsea! I've had the pleasure of driving many Landies, and on the roads they can be cumbersome (especially with a bit of slack in the steering box!), but point them at a field, down a dirt track, through a flood and they're superb!