By betting the turn we could fold out/charge a lot of hands that are behind but have a fair number of outs (AK/AJ/KJ/XdXd...). And since we would be overrepping our hand (let me know if i get this all wrong) we would know exactly where we stand if we bet here.

As for the free card we are missing out on if we bet here, what river card do we really want to see? a J? not really. a Q? we could still be in trouble.