And as on my buses, a child has paid exactly the same fare as an adult at peak time, why should an adult be more 'entitled' to the seat anyway, if both the child and the adult are fit and healthy.
I would expect my DS1, who IS fit and healthy, to give up his seat to anyone infirm, old, disabled, pregnant, holding an under 5-7yo, and people who genuinely ask him politely. Other than that, he's stating put.
If a fit healthy adult expected my fit healthy DS1 to vacate the seat for them, why should he? He was there first, and has paid the same fare. Why does a fit healthy 21yo take priority over a fit healthy 10yo?
I don't get that either. We are all human, a child is no less human than an adult, so why should they have to act differently?
A fit healthy adult wouldn't expect another fit healthy adult to move off a seat for them, they'd be considered rude and cheeky to even ask - so why is that any different for children?
Surely a child is just as deserving of respect as an adult?