A strange life

OP's account is very vague, and that lacks details about her past life with parents. She believes her parents didn't do anything to her. But she is a master's degree holder, who is married and living in the first world. Her post didn't say anywhere that someone else sponsored for her studies, marriage or decent life back then. So, it could be safely assumed that OP did receive decent care from her parents.
Her sisters were also graduates.

Now she compares her life with her cousins, whom received commendable help from her dad. No where in her post it is mentioned that her cousins' fully depended on her dad; hence he paid for their luxuries. They might have received reasonable amount of help from OP's dad in addition to whatever their parents did for them. Which made them lead a luxurious life back then compared to the OP.

A man has responsibilities towards others. Of course primary responsibility lies with his immediate family.

OP's mother's acceptance and silence to his helps towards his needy extended family makes it as a reasonable thing.

Even wives should be generous enough to let their husbands support their needy family members if their immediate family's fundamental needs are met. Although there is always a ratio as to whom to support what. It can't be 80% on others and 20% on family.

However, there are people who wish to have 100% to them for whatever the reasons. There is no end to our needs. So they think they deserve everything that a bread-winner brings home.

My dad and mom had responsibilities towards their siblings/parents back then. Dad supported our family sufficiently. Even then we depended on scholarships and part time jobs when we were studying in abroad.
Dad could have spent every penny of his earning on us. Thus we could have lead a luxurious life back then.
But he fullfiled his other responsibilities too. That too with the support of us, as we had to adjust so much. This is life.

A man doesn't automatically cuts off his relationship with his extended family. If unexpected circumstances demand him to support his extended family, then he should try to somehow balance it. He can't wash his hands, and say I am now married.
Also, asking a responsible man to never think of making a family is cruel. as long as he can manage everyone concerned, it should be fine. JMO