I can not speak for others, in my case I was raised as a Catholic, and after a few wasted years in the WT, I decided to come back.
Believing in God or not is a personal decision, that should be respected.
I do not try to convert anyone to Catholicism, but don’t like it when people insult it either.
We as human beings are spiritual beings, and not recognizing this part of ourselves cripples us in a way that no amount of logic can make up for.
There are many mysteries in the universe, and humans have always wondered about them. So, no I don’t think it is a rebound to look for another religion to fill you spiritually.