Most of us are nice. Personally I like that. Why? Because assholes are annoying. They distract, disrupt and disengage. There is an in-between... The "neutral" people. They get stuff done and they're cordial sure, but they also don't go out of their way to help more than they have too. They're not assholes, but their not very helpful either...
Why get on their case? People are people and you can't change them. But when you think about hiring, it does matter. When you think about building a team, it matters. And when you're trying to express or build a brand, it matters.
Hiring for a position
I hope it's common knowledge that bullies and assholes are considered a bad hire. But what's the harm in hiring a neutral person? Well, they're not going to take you further. Push boundaries, or care enough to spread good ideas or concepts from within. With neutrals it's crap shoot. They might help you... or not. Are you ok with that?
Building a team
Similar to the last point, typically a neutral will sit back and be comfortable on the sidelines. They're not going to take an active role in moving the needle. They'll blend in and actively control their comfort zone - it doesn't matter to them if the original plan is still relevant, or if priorities change.
Expressing a brand
We see this one all the time. Neutrals that are a part of executing a brand experience - just shouldn't be. I've never seen a neutral person do this right. They don't talk the talk, or walk, or behave the brand. They just don't care enough. Whenever you've had a bad brand experience nine times about of ten it's because that person just didn't understand what they're role really is... Or again, they just didn't care.
We all know about the assholes... but I'd advise watching out for the neutrals. While they seem harmless I'd argue they're almost worse because they're harder to detect and deal with because at the end of the day, they're not really doing anything wrong-ish... right?