The rating system is for mongers and humans that dont understand attraction.
The Japanese spend a lot on the packaging of gifts than sometimes what's in the package, this example should give you a clue, the so called 9s and 10s packaging is to attract, few if any will look like a 10 if you stick them in sloppy clothes no make up flat shoes looking like they just did a days work in a rice field.
Some of those you say are a 6 can look like an 8 done up, as for some of the guys beating around Thailand with 3s well in my eyes they wouldn't suite me, but im not foolish to think that there is not feelings and attraction from both sides.
For me my preference has always been for women well groomed and who know how to dress well, theres plenty around, especially in BKK, now these women are not going to look like a model every hour of the day but often enough, I learned a valuable lesson when I was about 30, there was this office girl who use to walk through the factory and often passed me, waist down she was exceptional, flat chested and a bit of a honk for a nose I thought at that time ugly, for 6 months we never spoke then one day we did, from that time onwards I got to know her fairy well, her personally shone through like a star, the lesson was never judge a book by its cover this woman ended up looking very attractive to me.