But the whole idea of the tazer is a less-lethal option where firearms would have been used. Do you not think this represnts a slightly dangerous focus creep from the original intention?
Tasers can be used by the police when officers are facing violence, or the threat of violence that would require them to use force to defend themselves or the public. That certainly appears to be the case in that video (I note that the video doesn't show what the man was up to before he was taken to the ground). I see no police brutality here.

The first two times I watched it it did look like all of them were to his head, but I can see this isn't the case.