The tag is doing better than I thought. By my count, out of the 50 newest questions with this tag, 16 have been closed, and 8 have been migrated.
That said, of the ones remaining, I still feel a good deal of them have been inappropriately tagged. There are a small handful where Arduino is the ONLY tag, and we should certainly find a way to stop that. It will be hard to convince me that in that case, the tag has any meaning at all.
The rest look sort of on the OK side, though. My biggest concern would be that the askers don't learn how to find their own answers if they only know to convey their question as "Arduino", but that doesn't look like its a huge problem.