“When community is your discipline, the core of your work is focused on understanding and putting into practice the development of communities. You might also understand and apply marketing, support or other practices but they’re traits, not your core discipline.”
David Spinks, as he often does, describes succinctly what I rant about regularly: Community is a discipline, and the more you try to make it a subset of other departments the more it fails. Other departments can adopt community-focused strategies (please!) but it will never make sense to say that the Community team is part of the Marketing team.