I'm french and english is like my 3rd language and in my head, a ratchet is also a tool. The OP seems to like to tell it's a simple thing, but I have no idea what he talks about and he goes here and then raging that it's not his responsability to make himself clear of what he wants to talk about. Maybe he think he's smarter than anyone else by using that word and not explaining it, but in the end this is a japanese game with an internationnal community, so, of course english is not at the center of the world for everyone.

So, I would like to asks the situation but since I don't know what he means, it's hard. My guess, since he talks about plat people with bad KDA/damage, is probably because he encountered people who tries out other job in ranked. Since you can't fall down from plat to gold, if you are learning a new job, ofc you'll be bad with it but it won't affect your rank while it will makes the other teammates suffer. But that is also true in many games. This happens.

Anyway in the end, it's probably another "get good" or "get lucky" situation. It's frustrating but it's not all games that are like that.