It's a good question. I think the reason component generally follows afterwards, acting like a form of confirmation bias to justify the choice.
I'm generalising now, but you generally never seen people exiting religious debates convinced to convert to another faith. Generally the 'losing' side will just fault their debater.. like it was a football game of sorts.
Generally when I listen to witness testimonies, of people who convert to Islam or Christianity, there is usually an emotional tie-in or hook of some sort. People will often say they felt lost or hopeless, or had no sense of meaning.. or somesuch.
But maybe I'm overthinking this.