I don't even pay attention to the ratings at all, so if I have read any below that rating, that's why. presumably people are deciding to read based on things other than the rating, because the rating can be skewed by so many other factors and because other people's criteria and rating scale for a story will be different from their own. it's not like ratings are any more helpful or objective than any other detail a person could decide to read for.
Ratings dont mean much, especially when it comes to manga. Some of my personal faves are below 8.5, just to name a few:
https://www.mangago.me/read-manga/two_in_six_billion/
https://www.mangago.me/read-manga/mofuku_no_hanayome/
https://www.mangago.me/read-manga/kimi_wa_boku_no_koto_o_suuhai_shisugiteiru/
https://www.mangago.me/read-manga/kimi_ga_inaku_natta_fuyu_no_umi/
https://www.mangago.me/read-manga/tomodachi_hitori_dekiru_ka_na/
https://www.mangago.me/read-manga/sin/
https://www.mangago.me/read-manga/ibitsu_itoshiki_himitsugoto/

im bored I wont judge im genuinely curious cuz theres always people that actively read them and I can sense the yaoi aint my vibe