No one starts off being the best that they can be- this is just part of her character development. I think part of the reason why there's this extreme dislike for her is because her character has not yet been fully fleshed out. I know of SO many characters in television, movies, books or games that I started off hating and now absolutely adore(for example, Sansa from GoT).
She's just incomplete, as are a lot of us.. It is up to Ragnar, now, to redeem her character.. if he does it the right way. And I completely understand your position on her.
At no point did I say 'EVERYONE SHOULD LOVE ZOE' I said everyone should be aware of the significance of a character like hers, and clearly you do. Even if you do see her as an annoying, mundane, trivial character, you are aware that she's in a lot of us. Including that Blowhard character, who's in severe denial.