On writing gush-free reviews

I was recently reading a first novel by someone I won’t name. The cover carried a quote from a fellow YA writer which suggested that the novel was utterly marvellous and gripping. Inside were a dozen more such quotes from well-known writers. Now of course, I understand that writers want to support other writers they know, and it’s also possible that these writers share an agent or a publisher who asked them to read and quote. But can you trust these quotes? Probably not. All that gush strikes me as so much luvvy back-patting. (Though I will say that I did enjoy the book.)