npub10avzjgtrx8uldhkn9cp58yv2f37g8kal97w67m0vqx5tw8me60mqzsr788 (npub10av…r788) npub1gsm90pjumqekhq83ark3jc4nm43lvz2hvvv7nn2g6hgthayfkwzsv75y8l (npub1gsm…5y8l) Yes, opt-in is consent. What exactly have you consented to? When have you specifically ever consented to a malicious server receiving your content? When have you explicitly consented to people, many of them bad actors, following you and sending you messages?
Regarding why the Fediverse-at-large prefers opt-out by default, it's pretty apparent to me: software engineers and server admins prize visibility and discoverability over safety and consent.