@filippo yes, people were quite unhappy/anxious when mastodon introduced /explore and public timelines from what i have heard. i wasn't around for that.
about the explicit consent part: follow requests/private accounts exists, that's seen as the consent mechanism from how i understand people. people who care about explicit consent have follow requests enabled.
even without that enabled, the user has clear insight into who has a copy of their posts. that is entirely missing with many scrapers.