That was the argument made by Bolsonaro. I know he's using it as an hypocritical reason to carry his own absurd acts. It's a race to the bottom, but that's true.. other countries cannot accuse him unless they're clean.
I take it Bolsonaro is a Brazilian government official. This is not how "taking a deep look in-house" works: if we argue that we should look in the mirror before looking at them, they can't use that argument to wish away any changes required in Brazil to keep the Amazon in a reasonable state. They should take a deep look in-house as well. And if they wish us to help with that (development aid from wealthy countries), they are welcome to ask, since it benefits us all.