It's just a personal pet peeve since my siblings and I are 3/4 Mexican and don't necessarily look like what some expect.
I am also half-Mexican on my father's side and am extremely fair, though I do have dark hair and eyes. My grandmother had green eyes, and fair freckled skin like mine; her grandparents were born in Spain. Meanwhile my dad's half-siblings look very different from he and his sisters are because their father has more native Mexican ancestry. So I hear you on that one. I "get" why that's a perception out there for a lot of people, even if I know it's not the truth. Mexico is almost as much a melting pot as America, in some regions. ;)
Re: Ronnie and Matt: YES. I love that he played up his working relationship with Brad being his favorite part of that show because I absolutely believe that their getting along so well and what they made of that relationship is precisely why the resolution of Jamie's LOUK arc was as painful as it was. I didn't see that coming when the show first started, I don't think anyone did. But they made it sing.