Some people aren't bothered by the way Zoey feels about the MC, some people are bothered by the way the MC feels about Zoey. It's something out of the player's control and can sometimes be frustrating.
I understand that compeletely, because like I said, the MC definitely was written to have moments of insecurity and he clearly cares about her still, how could he not.
This doesn't however explain how this would make anyone dislike
Zoey more, I mean dislike the writing sure, or even just dislike the
MC.
Zoey however hasn't tried to interfere in the MC's relationships, she knows he's in a relationship on all the paths where he is in one (except Bella), and hasn't tried to do/say anything to hinder his relationship(s). She is still in love with him, that much is clear, but that's completely understandable, and even when she started to feel jealous/overwhelmed, instead of making a scene she ran and removed herself from the situation.
Zoey is great honestly, not my favorite, but I really like her. The MC just needs to sort out his feelings, and under the players control, will keep his current relationship(s) intact. He won't let Zoey get in the way of that, nor would she even want to, and for the players who like Zoey and want to get her back, will eventually get that option.