From a broader perspective, the development of the last generation of this society relies on today's old people, from the former culture and spirit of the transmission are by their transition to us, which is this generation can be a normal person to do the important conditions of normal people.
So the people who gave you life and dignity, and why don't you respect it?
You also have old age, when you are old you want others to respect you, so now you also need to respect the elderly