Yeah I'm not finding Negan very scary at all really, but that's not JDM, it's the writing/production. Part of it, I think, is that we're presumably meant to find it intimidating because of how all-powerful he is. Rick is broken right now and sees no way out but to obey the Saviors, but we the viewer aren't. Since very early on in the season we've seen how Negan gets his power from bullying and intimidation, and while some of the Saviours, I'm sure, are happy, some clearly are not, and so it's only a matter of time before Negan loses his power. So as a result, he doesn't feel that scary, and it's just a case of waiting while they drag out the story some more.