Something I try to do, if I want to write an unfavourable review, is write a few positive reviews for other companies I've had recent positive experiences with

Something I try to do, if I want to write an unfavourable review, is write a few positive reviews for other companies I've had recent positive experiences with first. I figure that this gives my negative review some credibility, and it also helps the good businesses. I wonder if actually enforcing this might help things. If someone can't find anything positive to say about five other companies, I don't think I'm interested in their negative review.