DFC, sorry for the late reply but your bus analogy is a little faulty IMHO.
How much is it to travel cross London on a London Bus? They don't allow wheelchairs either. However, us tax payers have paid for the replacement of a large portion of the fleet with low floor wheelchair friendly busses!!
They
do allow wheelchairs, and if you're disabled the journey will cost you £0 - see
Freedom Pass. You could also book assistance for any National Rail (=GB train companies) journey -
National Rail disabled assistance - and that assistance would be free.
Back on topic, I think the company should have paid for his wheelchair assistance from fares revenue, as any other airline would, and if my ticket costs 50p more then I'd be glad to pay it. If only treating fellow humans with a bit of respect were that cheap all the time.
Sorry if that's a bit
but it's what I think!