Can there ever be a good reason to leave The Church?

Imagine a family that has been Catholic for, say, a thousand years.

What happens to the one who breaks the 40 generation chain and leaves The Church?  Does his or her punishment become more or less ameliorated by the reasons for leaving?

Or, is there never a good reason for leaving?  Is even thinking that disobedience is justifiable a great spiritual mistake?  Jesus was clear about His Church and it origin:  “Thou art Peter, and on this rock, I build My Church and the gates of hell shall not prevail against it.”

Therefore, if a person thinks that The Church is wrong about something, they are saying Jesus did not tell the truth and the gates of Hell have prevailed.  Can there ever be a good reason to leave The Church?

Still, people do leave The Church.  Why?  What could prompt such a terrible separation from His Body and Blood?  What deceptive force could make a person believe that Heaven could be easily entered by those who rejected His Sacrament of Forgiveness?

Some conclude that only vanity can prompt such a terrible mistake.  “Pride goeth before a fall.” many say to describe that awful rupture.

What happens to his or her descendants who grow up without the Sacraments?  Is their sin added to the original apostate’s?

If an apostate’s descendant returns to The Church, can the one who broke the chain be “prayed” into Heaven?