I think it should adhere to the 'enable direct editing of tags in the main panel' setting.
Steven actually did that at the start of 3.0, but several users complained and so it was reverted to the old (current) behaviour.
Hm, funny. Reading that back, it looks like it had been an oversight that it had been allowed for 2.5.
When it was done right (in my opinion) in 3.0, at one moment one user couldn't change the rating, since he had unknowingly disabled 'enable direct editing ...'
It looks like that was not a complaint, nor a request, but it was immediately reversed to the old 2.5 behavior anyway.