I've seen this too. My conclusion is that this happens when people who are strong communicators and networkers - influential even if they don't think of themsel

I've seen this too. My conclusion is that this happens when people who are strong communicators and networkers - influential even if they don't think of themselves that way - either misunderstand the need or value of some component, or they wilfully use the project to do a thing that they personally want to do. This "project as a vehicle for something else" is really catastrophic and is often a way for someone to exit the organisation with a gilded CV. What's important is that it screws everyone else. On the other hand, the obsessed super engineer is not being malicious, they believe wholeheartedly that they are right. The thing is to recognise which is which... one is a cancer that must be cut out fast, the other is a hugely valuable contributor who is misaligned (and in this case much listening is in order as it might be the project is misaligned).