I'm not talking about unnecessary (nor incidental) complexity. That is a whole other can of worms. I am talking about the complexity required given what you need to a system to spec. If choices are made to introduce unnecessary complexity (eg. "resume driven development" or whatever you want to call the proclivity to chase new tech) - that is a different problem. Sometimes it can be eliminated through practical considerations. Sometimes organization politics and other entrenched forces prevent it.