Well, constructive criticism is great in theory but a trifle counterproductive in public. Once the recording process is done, critical reaction can not alter the product. It can, only, affect the sales. Perhaps, if the critic is really interested in helping the artist, a privately communicated critique would be appropriate and useful. But expressing negativity about the recording in print can only be injurious to the success of the project. I just finished my first solo CD and, while I was receptive to criticism during the recording phase (In fact, I dropped one song because of negative reaction from respected friends), now that it is time to sell the CD, my watchword is, "If you don't like me, lie!". I suspect that, if they were honest, all recording artists would say the same.
That said, I think that the review that Mary received was relatively kind and pocked with just enough barbs to make the critic feel useful.