Agreed. That just really wasn't necessary. Only time that truly made a difference was in "Lethe".So, we would still be blaming Fuller for making Michael, Spock's adopted sister.
Her and Spock in season 2 could easily be written as close friends and it would have done pretty much the same as what we saw.
Making her Spock's adopted sister only was trying to force the audience to care for her story instead of her being a character that actually stands on her own merit. Tying her so closely to literally the face of the franchise telegraphs to the audience that the producers don't really believe in her enough to carry the show and was just a cheap gimmick.