I don't think it's OK for attorney generals, who are supposed to represent the public, to be acting on behalf of a business or an industry group, regardless of their adversary's size. It was compounded by the appearance that the prosecution was essentially outsourced to competitors. Per the NY Times article in the comment: "they assigned a team of lawyers to prepare draft subpoenas and legal briefs for the attorneys general. And the groups have delivered campaign contributions". Other articles I've read discuss how the MPAA's law firm actually coached the AGs as to what questions to ask and provided talking points.
Some people however feel such actions are acceptable given Google's dominance. AG Hood likes to say Google could do more and cites the things it does voluntarily. However, it doesn't matter if it could do more; the truth of the matter is there is nothing that says they must. The AG and some people want Google to live up to their personal moral code which would be great if we all had the same moral code. Unfortunately we don't. So if the complaint is Google should do more then we should adjust the law instead of trying to punish them for not doing more when simply asked.
The only thing certain is that whether or not you believe the AG should or shouldn't be getting such direct "help" or that Google is so big such "help" is warranted it will continue to create strong opinions both for and against.