> the skills to build good systems are not related to working effectively with others

Yes they are if you're talking about the types of systems that large companies have. It is in fact so difficult that I believe it's a considerable advantage to have scopes small enough to be manageable by a single engineer, but inherent complexity is often well beyond that, especially for very profitable business engines.

There isn't a single work project that I've been part of in the last ten years where communication wasn't important. If you work with anybody else (and if you are writing software for other people to use the then you should be), then communication is extremely important to build good, effective and useful systems.