respect and appreciation V.S. shout and accusation

Today, when I was travelling train from Central to my home, I heard the conversation from an old couple who are around 65 years old.

Man: How long does it takes from here to home? 20 mins?
Woman: No, around 15 mins.
Man (rudely and impatiently): don't argue with me!!

The woman didn't reply the man after he shouted at her however, the man keep shouting "always argue with me, there's no difference between 3 and 5 mins, do you need to count in seconds?!".

Before the man asked the question to the woman, I supposed that they didn't know each other as they sat in different roles of seat and the man sat behind of the woman. For me, it's so strange that an couple (I guess) sat separately and they both occupied double seats. I usually sit with my friend or parents when we travel transport together. But something happened later on that made me understand why they didn't sit together.

When the train was approaching to the station that they got off (I got off at the same station), the man firstly tried to went up the stair to the door. As the train was still travelling, he walked so hard and hold the hand rail tightly. He couldn't walk properly and his hand was holding a walking stick. I was surprised that the woman didn't help him or hold him because it seems that he would be so easy to fall down. I don't know what happened between them but I know they must have a very bad relationship.

It makes me think of my host mother and host father. Although they have got married for nearly 30 years, their relationship have been kept very good. My host mother always praise her husband every time when he cooks some good food for us.They know how to respect and appreciate each other.

What makes so different between these two pairs of couple??

What I think is that more respect, appreciation and less shout and accusation are very important for keeping a good relationship. It doesn't only apply on love relationship, but also friendship or even relationship with parents.