In project management a project is not something to ‘grow new actions’, it is a methodology to manage a large amount of (pre-defined) actions to make sure the project meets it’s deadlines, stays on budget, etc. Other concepts like Critical Path Analysis and Resource Leveling come in to play, stuff that GTD can’t handle at all. So when someone talks about ‘managing projects’, they are probably talking about exactly that: ‘managing projects’, and not about ‘managing next actions by using something we call a project to keep them grouped towards a common goal’. There really is a big difference ;-)