My motivation is to promote financial freedom and individual sovereignty by advocating for "a purely peer-to-peer form of electronic cash". I hope that is what we are all doing here.
Advocate for anything you like. Just keep in mind that your preferred use-case may not correlate with the desired use-case of other people. No one gets to unilaterally dictate how other people choose to use the protocol. Even if you don't approve of what they are doing, doesn't mean you can prevent them from doing it. You do what you want, they do what they want.
All you can hope to achieve is educating them that silly pictures are a scam and have no value beyond what the greater fool is prepared to pay.
It's also not correct to blame developers, because other blockchains that do not follow the same code as Bitcoin are also plagued with silly pictures. This stuff would exist regardless of what developers have or haven't done. The only thing that would be different is the
quantity of silly pictures. There's room for more of them in Bitcoin versus coins like DOGE, where they can't affordably spam as many of them.