I think reviews are useful when they point out that you need to adjust the cooking time, or that not as much liquid is needed. For example, some pasta sauces call for a 28 oz can of plum tomatoes, and then for an extra cup or more of water. You just about NEVER need extra water, and people ought to point that out.
But the ones I find comical are those in which the reviewer changes just about everything, and then say it wasn't any good. Ideally, we should try them exactly as written, and then make any changes we feel are necessary the next time. If there is a next time.