Because there's no platform or ideology on earth capable of paid advocacy besides the oil industry, and certainly no political movements ostensibly grounded in "green" advocacy.
If you are going to claim that a position is invalid due to financial influence, you really have to do the basic math of how much profit is actually at stake on either side of the argument And weight the impact of said influence appropriately.
Who has deeper pockets and more to loose if anthropogenic climate change is real and caused by co2 emissions? If you truly think it’s the folks that are cutting grant checks to climate scientists, I have a bridge to sell you.