The Agile Master (aka Scrum Master) has to care; this is key to successful agile adoption. The Agile Master has to care because if they don’t, nobody else will. First, they must care about Development Process. Someone who cares about Development Process is motivated to make sure their team has everything they need to perform their roles with excellence. Second, they should care about Process Performance. Someone who cares about Process Performance is motivated to execute project schedules on time and on budget. Of course a person who performs the Agile Master role may care about many other things than these. That is what makes them unique and able to perform other roles on a project.
The Agile Master must be Strong or Strong(ER) to be able to successfully lead/mentor a team in the use of agile principles and practices. If the Agile Master is not Strong, i.e. the team is just starting out, pair up with an Agile Coach. They will help them Get Strong(ER).
The Agile Master should be Strong or Strong(ER). People who care about being on time and on budget are more willing to lean/lead towards flexibility when it comes to trade-offs concerning schedules, resources, and features. It is OK if the Agile Master is not Strong if someone else on the team is Strong, and especially if the Product Owner is Strong(ER).