Easy, the sentence, after search and thoughts, as I see it, seems to say parents are meant to make their children happy by freeing them (children) from upsets...
Happy Days (1933)
Children aren't happy with nothing to ignore,
And that's what parents were created for.
"The Parent"; paraphrased variants:
Children aren't happy without something to ignore, and that's what parents were created for.
Parents were invented to make children happy by giving them something to ignore.