Right, but what about when Alexis isn't romancing the MC? Then she has no reason to quarrel with Erynn, but the two still act as if they are quarreling. She doesn't drop by Erynn to visit, she doesn't look in on her while the MC is at camp, and she doesn't help look for Erynn when she's (presumably) lying behind a dumpster. My whole point is that the relationship between Erynn and Alexis should seem very different if the MC turns Alexis down, but it doesn't.
There are certain scenes that would take place "behind the scenes" that we don't get to see. Every interaction between characters is not possible. Conventions we make as we are reading, assumptions. If they are best friends, then we must assume that Alexis does visit her, call her, text, etc. we are simply not privy to those interactions.
If the MC is not pursuing Alexis, why doesn't Alexis look for her at the end of Ep. 9? My best answer would be so that we can see some of the other characters in action — John or Valeria. I do not think it was an oversight or an attempt to illustrate a problem between Erynn and Alexis. After all, if you were playing an Erynn route only, you would not "know" anything about the relationship between Alexis and Erynn other than they are best friends.
There are limits imposed by amounts of coding, rendering, storytelling, releasing frequency, etc. that restrict how much content can realistically be added. The story is not about Erynn and Alexis. Why would the author focus so much attention on that relationship outside of how it involves the MC?
He's been an annoying prick since his very first scene.
I've never seen a point to his being there other to make the MC look good by being a complete and utter jackass in every scene. Now I see his purpose was to be a dick to the very end.
It's weird because most "best friend" characters are usually likeable or at least amusing but Zach is neither. He's a moron and a creep.
I never saw Zach that way, as a creep or moron. Growing up in high school, one of my best friends was the guy who never had a girl but always desired every girl that walked past him. He would follow each new girl around like a puppy for days until he got tired of us mocking him. Nobody thought he was a creep or a moron. He just wasn't the guy anyone dated.
I am not so sure Nyx wrote Zach as the "best friend" character. He was the guy we used to be friends with. The player has the choice to recognize and be nice to him throughout the VN. Alternatively, the player can choose not to recognize him and really never be nice to him throughout.
I am glad to see that Nyx does not write all her characters like "the usual VN characters." Oh, and in the end, turns out that best friend of mine was a really late bloomer. By 25 he was the envy of a lot of guys, but the typical douchebag guy that girls fall for and then run away cursing men.