[spoiler]You’re biased in favour of the Starks because that’s the way GRRM wanted you to be.
The point isn’t necessarily about how the Starks and evil go together. It’s about twisting the traditional story narrative of Good v Evil and how good will always win.
For instance, in the books after his execution, many characters will observe how honourable a man Ned Stark was etc but will continue to remark, in the end he lost his head despite his perceived goodness recognised by both the readers and characters.
The same is seen with Robb. GRRM obviously deliberately emotionally invests the reader with the Starks and later the Northern struggle. You won’t be able to find a person who didn’t want Robb to beat the Lannisters and rule as King in the North.
That would have been the traditional Good trumps evil story but he distorts the traditional narrative through the Red Wedding knowing it’ll have a shocking effect on the reader who is quite emotionally invested in Robb by that point and naturally programed through other works to believe Good trumps evil every time.[/spoiler]