One must be able to perform to be of value but it is also important that your boss knows you. A simple example. You have a friend, who you know deep down can deliver jobs but not exactly excellent and a bunch of strangers who claim (with their own track records) they can do even better. I would go for my friend. Reliability.

Also, if a company is huge, higher ups need people to tell them what exactly is going on down below. Among those informants can be the bootlickers. Personally, as long as they are not spreading misinformation, I don't mind them much.