What is the ruling on dealing with parents who did not care for their children until after their academic success, out of greed for money or benefit?

The mere separation of the parents does not permit shortcomings in fulfilling their rights. Rather, it is obligatory to constantly honor them and obey them in what is right. Their right to dutifulness does not cease no matter how negligent they may be. Allah commanded companionship with kindness towards a polytheist parent who orders his child to commit shirk. Therefore, it is obligatory to honor one's parents, treat them with kindness, and obey them in what is right.