People want pixie dust. Complain to Disney. You don't stand in a DME bus. You don't stand on most of the attractions. The end of the day many passengers would prefer not to stand. Some people have severe disabilities, some hidden and some minor. We don't get to judge people who chose not to give up a seat, we don't even know their circumstances.
I suspect people will get better (OK probably the same) results motivating Disney into running enough buses to provide seats as they will convincing tired guests they should give up a seat to a guest who is more worthy of a seat.