In my professional experience as developer I'm terribly disappointed with so called "scrum masters" dedicated for the job, the teams that I worked in that implemented scrum correctly were the teams where the team itself took the responsibility to do it right on themselves.

...and we come back to one of agile principles: "the best architectures, requirements, and designs emerge from self-organizing teams". I think the scrum itself says to not confuse the job title with the role and I believe that's what happening in many cases. But it all looks good on paper, we have scrum because we hired scrum master so management is happy whereas in reality it is not true - I saw it many times.