It's not about budget.
Once upon a time, I saw a. production of a musical in a tiny performance venue with a small stage and a set made predominantly out of cardboard. Despite it's shoe-string budget, this still remains in my memory as one of the greatest pieces of theatre I've ever seen. Because the actors were committed (and very talented), the director had a clear and original vision and the story was beautiful. You Should See It reviews artistic and technical choices, commitment and quality. The reviews take into account the audience the theatre company is appealing to, and the limitations that often surround amateur and independent theatre companies.
A glowing is indicative of a production that showcases originality, a clear vision, committed actors, clever artistic choices, solid technical teams and a performance that is enjoyable (be that humorous, thought-provoking, saddening or other-wise).
Anything less is indicative that there could be improvements made. Sometimes these are technical, sometimes these are creative and sometimes these are performance based. It is never about damning a company and leaving it at that. It is about encouraging smart creative choices within their capabilities.
It's about quality and it's about commitment. Regardless of whether your set is dripping in flashing LEDs or made up of cardboard cut-out trees, all companies are capable of presenting "five star" production.