Agreed. I feel that it’s pretty obvious to most any reader when a review is helpful or not. I don’t think they should all get deleted. I simply think they should be move to another section of the forum, and save the reviews section for high quality postings to make it easier for people to find what they need, rather than having to sift through “This yo-yo is crap!”
They already have the excellent guidelines. The rules could simply be “Follow at least 75% of the guidelines or your review will be moved.”
The issue though, of course, is that it will be mostly case by case, as writing up rules for a good review is very, very, hard. It’s an “I know it when I see it, but can’t define it.” The government has bumped into this issue many times when trying to define laws.
Perhaps it could just be stated that if your review is reported and the first Mod who looks at it doesn’t like it, he needs to get it seconded by another mod to have it removed or moved. That should prevent threads from falling through the cracks. And if one gets moved that shouldn’t the OP can report it and appeal the original decision if they feel it was unjustified.
Another option is to have someone who wants to take on the project collect good reviews and put them all in one place. Perhaps a stickied thread, or a blog, or website. I don’t have the time for it, but hopefully someone else out there does!