Sure, it’d be easy to do that but that’s true for everything with an open API really. I don’t think that makes Lemmy less privacy respecting. The only thing a harvester could grab is the things you’ve chosen to post publicly. Is that a good thing? No, not really but it’s certainly much less invasive than being on a site/app that harvests both that and fingerprints your devices and tries to get all your OS/location data/etc at the same time.