I've wondered about that. You hardly ever see wheel chair users using the space with their back against the padded bit, as they would have to come onto the bus then turn around to reverse into that space avoiding the pole, which looks very tricky. I've never seen anyone do that who is propelling the chair themselves. Normally with a full bus and people standing and baggage everywhere, it would be impossible. I've seen the pole get in the way of big wheelchair user so they aren't able to fit into the space. Mean while that pole really gets in the way of older people with trolleys and and baby buggies.