It's more than that.
Ohio State also had Terrelle Pryor as a QB and he was dumb as a rock as well. It was so bad announcers would make fun of him because he could not complete a sentence. He would talk in fragmented sentences, much like you see Senator Fetterman doing today. Then, being the leader of the team, he got involved in a tattoo scandal that cost the coach of the team his job, and suspended players and records to boot, all because he was an idiot. The only reason he was the QB was because he was such a gifted athlete.
Without a doubt, the most important attribute for a QB is their intelligence, both in relation to performance on the field and off. Arguably, the performance off the field is more important for a myriad of reasons.
In the NFL, he tanked quickly, which was predictable.