1. Why do we bet turn if we think he will call river with one pair? Contradicting strategy.
2. Regs at these stakes are slowplaying here a ton.
3. Our perceived range is very strong, even 78s hit.
4. Villain can only beat a bluff.
5. Zook isn't a maniac.

So what if his range looks weak, he can't play KJ like this profitably and he very likely doesn't. Neither would you or me. Against a fish or weak player, of course easy bet, not against a reg with almost 3AF.