what happened to the players in this game?

I have 300 hours, played beta through season three, and i jsut came back and have been playing ranked cashout all day. the players in this game (for the most part) are absolutely atrocious. not just lights, but mediums and heavies who have no idea how to play the game, im talking running halfway across the map to fight randoms, bum rushing every room imaginable, disconnects, hell, half my ranked games i only spawn in with 1 teamate anyway. has it been like this for a while?