Re: not neccessarily very good at brown-nosing...
"I've known people who've had great ambitions, not to be "manager" or anything like that but to be the best they can at their job"
Exactly this. I worked for a famous TLA that would see this as performance below expectations... It was so damaging to everyone.
I now work for a different large global who has just introduced, as the result of feedback, the ability to stay on a non managerial path yet still have the same recognition, goals, promotions and rewards.