I believe you mean, "agree with me on gender and sexuality". When you take away the tendentious wording, it's a lot less clear that it "should be a given."
My understanding is they only scan for content if it's being uploaded to iCloud. Scanning on the phone, yes, but only if the image is to be sent over the network.
And they seem to be doing that because they both 1) want to enable e2e encryption for iCloud images, soonish, and 2) don't want to become the world's most popular child porn storage and sharing platform.
I get the arguments for why the fix for #2 is too dangerous to be worth it, but also get why they'd be inclined to choose it.
Ah, but CZI is not a non-profit, it's an LLC, making it an even more efficient vehicle for legal tax evasion, PR, and power. It also allows Mark and Priscilla to make funding decisions affecting entire communities on a whim, without the involvement of cumbersome board members.