Personally, I write off Gloomhaven because it's a tactical miniatures game (something I've never cared for). There are other high ranked games, like Caverna, which I write off for similar reasons.
Entirely not what I suggested.
Amazon has a large registered user base (who can apply ratings), and only a tiny percentage of those are interested in religious books (or, these days, you could probably say only a v.small percentage of Amazon customers are buying books of any sort).
BoardGameGeek has a user based almost by definition exclusively of people who are interested in board games.
GP's suggestion that niche product ratings could / are skewed by people unfamiliar with the topic doesn't apply so well to niche communities, especially ones with effective moderation.
Disclaimer - I've been on BGG since 2012, own Gloomhaven (but haven't played it), and consequently haven't rated it.
I do think the boardgame community has enough subniches that it's not immune to this problem, though.
I wouldn't self-describe as a board gamer. I monitor the forums & reviews a bit, and have been going to a local meetup for a little while.
But it does feel like board gamers tend to be quite familiar with games outside their 'preference zone' -- perhaps more so than other work & hobby areas I've experienced. Anecdotal, to be sure.