How important is it to be poilte to old people even though they are often rude?

Dear [Name], I think, a polite manner for old people is a traditional habitual. We must respect old people in tradtional aspect. But now a days, it seem to be changed a lots than I thought. As you know, all of people are getting old, sometimes we will die. I know, you know, everybody know. But young person have no think about it. They don\'t think about the future. It is a fact to be a old person in the future. I respect my father and my mother. They have no even education time of elimentry school. But they gave a lot of love to me than I gave my son. All of them was much better than I did. My mother took care of grand parents and my brothers and sister, my cousin... but my parent did\'t said complain about that. They thought it was a duty. What do you think about it?