Being the second biggest polluter of CO2 pretty clearly refutes that “developing countries” are the biggest polluters. The US has a lot of problems, but I’m not sure I’d call it developing.
Remember how you responded to someone who was talking about the biggest polluters, and you couldn't attack that statement, so you changed it to biggest polluters per capita? That's where your logic failed.
Do you see that there was more to my comment than what you quoted in yours?