Yes, it is due to feminism. Men have no say about anything concerning legal/financial matters of their sperm. Have always believed there would be fewer unwanted/unprepared pregnancies if single men were legally able to 'choose' not to be a parent like women do. Equality is not.
In the case of sperm donorship, I think the father chose not to be a parent, just helping someone out who wanted a kid.
In other cases, it's complicated. Can a man tell a woman to have an abortion, because he doesn't want to be a parent? Can a man tell a woman, who, unplanned, fell pregnant tell her to get the baby, because he wants to be a parent?
Ideally, there would be communication on this. But if the final say would be with the man, rape could become the way to get offspring.
I don't know. Feminism comes in many forms, as does socialism, capitalism and what not. If it can be used for benefit, every ideology will be bent to get that.
Feminist influence in my country means shared custody, by default, after a divorce. It means the richest of the two partners, after a divorce, will have to take financial care of the ex partner, no matter what gender. And, alimony for a partner will never be longer than 12 years. If the marriage hasn't lasted 5 years, alimony for a partner will not exceed the number of years the couple was married.
The maximum of 12 years will probably be brought back to 5 years.
Alimony for an ex partner makes sense. I know couples where there was the agreement they would study in succession, while the other provided the income. If after 6 years one partner got a degree, and a good job, and the time had come for the former provider to quit a job and get a degree, and divorce happened, the one with the degree better pay for the then unemployed and studying ex-partner. The degree had been paid for by the ex-partner.
Trying to pluck money from a sperm donor, well, a state who wants that done can use all kinds of ideologies to get that. Interest of the child, to know it's biological father, and the right of the child to know it's father cares, at least in a financial way, is a nice one to use.
The "it isn't how god/nature intended children to be begotten" is another one.