I re-read your post and while it's not overly aggressive it's the difference in tone and approach that get you. The original poster was like the hippie encouraging home-made yogurt and you were like the school principal saying 'this is bull, store yogurt has scientifically the same benefits'.
PS: I also learned while writing this I can't spell yogurt. Thanks spellchecker!
PS: I also learned while writing this I can't spell yogurt. Thanks spellchecker!