I always fallowed the "separate content, artist and fandom" rule, so yeah, harassing someone just because they enjoy something that was created by a problematic person just sounds stupid, especially because they might just not know who they're supporting.
If you want to cancel someone, do not go after their fans with pitchforks and such, just inform them, and if they still want to consume the content, show them how to get it without supporting whoever you're canceling.
But if they still support the problematic creator after that... Then still don't go after them! You'll just give them a martyr complex and they'll assume a "us vs them" mentality, and then they'll just get worse than members of a creepy cult, trust me.