"It's because Greenpeace is a political organisation, their purpose is to be anti-corporation"

Where did you get that from? Greenpeace has a history of working with corporations to improve their practices and promoting the efforts of corporations to engage in sustainable production:

https://www.greenpeace.org/usa/reports/greener-electronics-2...

https://corporate.mcdonalds.com/mcd/sustainability-old/libra...

http://changeyourtuna.org.au/