It is the right of parents to be obeyed and honoured by their children, and for their children to offer supplication for them, even if they fall short in raising them and spending on them

Firstly: 

It is not appropriate to take knowledge
from anyone except scholars who have good knowledge, and knowledge will
remain so long as the scholars remain, then when Allah wants to take away
knowledge, He will take away its people. Muslim narrated in the introduction
to his Saheeh (1/14) from Muhammad ibn Sireen that he said:
This knowledge is the (foundation
of) religion, so watch from whom you learn your religion. 

Secondly: 

It is the parents’ right over their
children that they should honour them, even if they fall short in terms of
upbringing and spending on their maintenance. 

If the father does not give his child his
rights, and falls short in his upbringing of him, that is a sin for which he
will be brought to account and will be punished, but that does not justify
disobedience to one’s parents, which is one of the gravest of major sins. 

If it were the case that every time the
father falls short in his duty towards his son, it would be permissible for
the son to fall short in his duty towards his father, then all Muslim
families would be ruined, and the son would disobey his father or mother for
the slightest reason, and he would take his own opinion as a means of
disobeying his parents. Therefore he would say: My father fell short and did
not give me my rights, and my mother fell short and did not treat me like my
siblings, so he will disobey them and will think that they have no rights
over him. This would cause trouble in the family and in society. 

Ibn Baaz (may Allah have mercy on him) was
asked about the Islamic ruling on a person whose father – as he says – did
not play any role in his upbringing and did not give him any kind of care,
even when he was an infant, despite the fact that the father could have
spent on his child. In this case is it still obligatory to uphold ties
between the father and his son? 

He replied: 

Yes, the son is obliged to honour his
father, acknowledge his rights and treat him kindly, even if the father did
badly and even if he fell short. And the father has to repent to Allah for
his shortcomings; he has to repent to Allah from his shortcomings with
regard to his upbringing of his son, but this does not justify disobedience
on the part of the son. Rather the son must honour his parents, even if they
fell short with regard to his rights. Allah says concerning the rights of
the disbelievers, in the story of Luqmaan (interpretation of the meaning):
“but
behave with them in the world kindly”
[Luqmaan 31:15], even if
they are disbelievers. What is required of the son is to treat his parents
kindly and honour them, and to interact with them in a nice manner, even if
they fell short with regard to his rights. 

End quote from the shaykh’s website:

 http://www.binbaz.org.sa/mat/9310

With regard to the verse in which Allah,
may He be exalted, says (interpretation of the meaning),
“And lower unto them
the wing of submission and humility through mercy, and say: ‘My Lord! Bestow
on them Your Mercy as they did bring me up when I was small’”
[al-Isra’ 17:24]. 

This is what usually happens: the parents
bring up their children, so the child should pray for mercy for them,
responding to the blessing with gratitude. No one deviates from that except
a few, and there is no ruling for the deviant. 

By analogy with what this person says, if
the parents, or one of them, was to die following the birth of the child,
they would have no share in this prayer for mercy, because they did not
bring him up when he was small, and the one who brought him up and spent on
him is more deserving of this supplication than them, but no one would say
that. 

For more information, please see the
answer to question no. 176847 

And Allah knows best.