They're both males with brown hair & occasionally sport a goatee?
Among other things
I think it's more than just that. For me, it's body language, the look in the eyes...things like that. He doesn't come across well, if that makes any sense. Granted, our society does not cast judgement based on those things, yet we've all had 'gut feelings' about people.
Michaels brother speaking out for him has done, IMHO, way more damage for Michael's side then good. His lack of care and compassion for Terri was blatant.