Is it unreasonable to expect children not to watch videos or whatever on public transport without headphones on?
If you don't want your children to have headphones because of their ears then take a book for them or colouring to do.
Maybe I am being unreasonable and grumpy but I've had enough of other people's children's video choice on my commute home today (and yes I've had young children and no I never let them do this on public transport)