That's called "finding a justification for unethical behaviour".

"Well overall it's better if I do the unethical thing because when you think about it REALLY it's for the best- and yes, I'll make some extra money this way, but that's unrelated to why I've searched my soul for any reason to make this okay".

Google et al aren't denying information to oppressed people. Their governments are. The companies have to decide whether they will be complicit or not.