For the same reason that young people tend to generalize. (ALL of a group are not the same. ALL old people aren't mean. Some are.)
Well it depends. They could have alzheimers disease, which makes them grumpy, or maybe there husband or wife passed away. They could be losing there hearing, or just be mad because so many ppl think they need to help him. Hope it helped!
Well said.. If you were a old person, and you never got the respect that you deserve for living a long life. Would you be mad? The younger generation today do not care about manners and respect for elders or adults at all. It's the society they are growing up in verses the society that the older generations grew up in.