That makes sense and I appreciate the insight but I'm mainly commenting bc of how odd your stats are-not hating but joining 2017 and having under a hundred comments is wild AF to me for some reason.
As for the user: could simply be someone who is more of a silent viewer and has a correspondingly low post count. Or the user in question is more active in areas where the count is not counted.
As for the rating of this VN, curious by your previous post, I read through some of the more recent ratings and have the following assumptions for the more recent 5* ratings:
1. the user in question hasn't had the VN all the way through yet, and is therefore a bit blinded by the better beginning.
2. service of one or more preferences. Quality plays a minor role and it is possibly clicked through from lewd scene to scene.
3. low standards. I see it often enough outside the AVN that qualitatively not good games are defended by the fanbase as if the said base were a mother lion defending her cub with her life. Pokémon, for example, is a franchise that has very loud defenders who cannot be argued with and any criticism is taken as if you were publicly using pages of the Bible as toilet paper in the Vatican.
4. trolls. Be it to shorten the distance to a hated dev/project, to lead the affected dev on a wrong track with his decisions or whatever. I could also imagine that possibly one or the other could be an experimental bot, because I have often enough 2-3-word comments on the corresponding VNs read in topics in their lack of content can be easily copied into any thread.
5. reaction collector. Reactions in the reviews are added to the total reactions received. I would assume that some people may hope to increase this counter.