When Rick figured out that dumb brain waves block his genius brain waves, he traveled back in time to ensure that a young Beth met Jerry, the most unintelligent person around. Making sure his grandchild would be born as the perfect shield.
Seeing his selfish actions clearly ruin his daughter’s happiness, he resents Jerry and takes out the anger he has at himself on his son in law.
And that is why Rick doesn’t mess with time travel.
you know what….I was close













