They're indeed different issues, but your original wording directly coupled the value of your data to the use of your data.
I am devaluing my data for Facebook.
I was arguing that the monetary value of your data to Facebook won't decrease much by reducing your Facebook activity. You're (now) making the argument that the scraping and re-using of data is wrong and that you don't want to be involved in that. Which I'm not disagreeing with. But that isn't your value to Facebook, that's your value to Putin / 4chan / whatever hellspawn makes those pages. Your face now, sadly, helps convince gullible people of some argument that's never yours.
that makes you personally culpable. Not legally, but definitely morally.
No, fuck that. You're powerless. You're collateral damage, the result of chance and big numbers that ostensibly lead to scraped, automated identity fraud. It's not your fault, it's the platform that shouldn't make automated fraud so goddamned easy.
Take another example: social security numbers. It is far too easy to get someone's number from some leak and use that to steal identities, solely because social security numbers in the US is the only personal identifier that is ubiquitous. That doesn't mean you are personally culpable of this shitty system. Maybe to the extent that you should let your congress(wo)man know about it, but other than that you are powerless.