Earlier quoted context omitted.
Reviews shouldn't be opinion, but facts. Those facts can then be disseminated to larger audiences. The incentive is to ensure that only factual information is claimed in publication so that everyone else can be as informed as possible, thereby (hopefully) allowing us to all make better decisions (and, perhaps, this could even accelerate the above described process).
Every time you use the word "should" you beg the question. Why, exactly, are incentives aligned to make it so? Or is the problem that the incentives are not in fact set up to encourage the desired outcome? Anything else is wishful thinking. People seldom do what they know to be right; they do what is convenient, then repent. It follows that one must make the right thing the convenient or rewarding thing if one wishes…
The incentives are 'aligned' that way because it is the only way to benefit. Publishing into an echo chamber (or void) is not science, by definition.