"just one rating isn't going to impact your game's rank"
Not "just one". It already happened multiple times.
I only provided last case as example. One user can rate all your projects (like it was in my case). I see you are also developer and you have multiple projects. It will be ok, if user will give all your projects 1 star rating (plus will insult you in review) only because he didn't liked your answer? I guess no and he will get ban immediately :D
"I don't see what's unclear."
I clearly explained problem and i think "Like" based rating system would work better then 5 star rating system. Less possibility to abuse.
Current 5 star rating system can be abused by users and developers, but "Like" system only by developers.