Honestly that sounds so basic that you could just be describing any elo from bronze to gold right now. Mind you, (depending on your server) Diamond 3 is not bad at all, it's actually in the top 1%. And yet what you just said sounds super simple and can be applied to people in silver 3 too. You don't climb to as high as mid diamond to then generalize ("in a nutshell) their entire player base to smt like that. It's like saying they haven't progressed at all.

So either you just don't know what you're talking about (pretending to be D3 while you're actually a lot lower, and saying things like "D3 = low elo" which is obviously false) or you're just in a super shit server.