Sadly, many people who don't do well take their feedback to mean that they need more code commits or comments. Some of them might even succeed at gaming the system for a short while due to a bad manager. The truth from my experience is that as long as you drive meaningful impact, and are able to convince you manager and others of it, you will be doing well. Falling back to silly stat numbers is the toolset of people who don't have enough achievements. In a way, good numbers don't mean good performance. But bad performance really does correlate with bad numbers. So people who are unhappy with their ratings will deduce that is the problem. It's aggravated by the fact people with good ratings don't boast about it (which is considered rude). I've noticed similar effects in college with grades. Judging by the vocal people one could assume the majority of the class failed at the exam, since whoever succeed will do well to not rub in their friends' faces)
* Personally I do use numbers in reviews, but only as a secondary way to backup my claims for what I did, or why it was important
* * If you are convinced that your manager and team only cares about stats, I recommend switching to another team or company when you have the opportunity.