There seem to be a confusion between the role of the ScrumMaster and one of a team facilitator. Jason Little recently wrote that you might need a coach, not a ScrumMaster:

So what is a coach going to give you compared to a Scrum Master? Scrum talks about a Scrum Master as the team facilitator, someone who is there to protect the team, remove obstacles and help the team function better. Essentially the scope of a Scrum Master is local optimization for the team.

A coach, on the other hand, will be focused on optimization of the organization. Often they are working and thinking on multiple levels and deeper when team output is exposing other organizational dysfunctions.

I disagree. This is a misinterpretation of the role of the ScrumMaster. Scrum is a tool that an organization can use to address hard problems. It is a tool to foment change. An organization that decides to use Scrum to address its issues is choosing very hard work. Only few organizations will fully take advantage of Scrum. The remaining organizations will try to use Scrum and run into ScrumButs. ScrumButs are the reasons why they cannot take full advantage of Scrum to solve their problems and realize the benefits. Each ScrumMaster is responsible for fighting ScrumButs by maintaining the integrity of the Scrum process, even if it is in conflict with the organization. This is much more than a facilitator role, right?

Of course, when a ScrumMaster starts working with a team, he or she might act as a parent, teaching the team how to self-organize. As the team gets more mature though, the ScrumMaster will spend more time working with management on the ScrumBut backlog to remove the dysfunctions of the organization. The ScrumMaster is not a team facilitator, it is a secret change agent!