Bc in the books, the only Stark that likes Theon is Robb.

Most of them don't even think about him enough to have an opinion on him and the ones that do dislike/distrust him immensily

So when people say he betrayed his family, or that he's a kinslayer i wanna bleach my eyes

His third pov in ACOK shows how bitter he is about it, he wanted them to like him, but the only one that does is Robb

They're broken mirrors of each other: both of them just want the starks to see them as family, they want to feel wanted, they envy and hate each other.

Theon is a trueborn son of a great house, an heir even, but at the same time he's treated as a squire and a ward when convenient, (he helps Ned and Robb), he's also seen as a hostage and a threat, never quite trustworthy. He says repeatedly that he never felt wellcome by the Starks and that the only one to have any affection for him was Robb. Theon dreams to be wed to Sansa, not because he loves her, but because them he would be a son for Ned. He envies Jon because even being a bastard he's loved by Ned (ln a way neither Ned or his actual father loved him), his sibilings (all of them) love him, even if Lady Stark doesn't like him, he is family in Theon's eyes.

Jon is a bastard, he's a shame that must remain hidden, it doesn't matter how much Ned or his sibilings love him, he will never be a true Stark in the eyes of westerosi society. He is trusted but his loyality is always at question, Jon is a threat to Robb's claim in many peoples eyes, like he wants his brothers birthright, and the worst of it all is: he does. He desperately wants to be a trueborn son, but he loves Robb deeply, more than he could ever wish to be legitimate. He envies Theon because he is a trueborn son, he is an heir, he will get to have a wife and children of his own, legitimate children that won't be called names.