Presumably, if they were considering a Tesla at all, they didn't actually need a large pickup. So, to spite Elon over some political beliefs, he produced several extra tons of CO2 and is going to be emitting more CO2 on an ongoing basis, even if his energy source is 100% renewable (unlikely) as even wind and solar still (and for the forseeable future) have non-zero CO2 emissions due to mining and production of materials.
I understand why people don't like Elon. He's pretty unlikeable, even if you don't disagree with his politics. I just dont' understand why they let it influecne their purchasing decisions.