It isn't bad writing if it shows the villain's hypocrisy. Furthermore, there is more nuance to it than that. In Maya's mind, Saint-14 doesn't belong because he was pulled "out of time", so to speak. From the moment he originally died. Right now, Maya is looking for a Chioma Esi who entered the Vex Network to look for her. She is right on that count, based on the Veil Containment logs. However, if [url=https://www.ishtar-collective.net/entries/irrealis]Irrealis[/url] is any indication, the Chioma we know eventually ended up with the simulated versions of the Ishtar researchers, specifically group 227.72 if the hoarseness of that Chioma's voice indicates her age relative to the others. In other words, while Chioma did enter the Vex Network, she didn't search tirelessly until she found the "true Maya", a Maya who was long gone in her obsessions. She instead found a Maya who didn't go down that path. If the two are reunited by the end of this Episode, I shudder to imagine how Maya Sundaresh might react if Chioma rejects her and what she's become. In this Act's opening cinematic, Maya mentioned she had "the tools to make her understand" if Chioma could not see why Maya's methods were necessary. I can only guess that it would involve using the Echo on Chioma.

The sad truth is, it's more likely bungie didn't intend for this to be an instance of arrogance and it's more like miss communication between writers since bungie likely had multiple writers working on different sections of the episode at the same time. I'm inclined to believe it's the later give how poor the writing has been for the episode as well as final shape and lightfall.

We are talking about the same woman who ran experiments on the Veil with no regard for the safety and lives of those around her. It's even inherent in her search for Chioma. Each iteration of Chioma that doesn't match the Primary Query, she erases through degaussing, effectively killing Chioma over and over again. Even in the event she finds the Chioma she is looking for, she seems prepared to force Chioma to understand why she considers her methods "necessary" if the latter doesn't agree with what she's done. Each one that isn't "her Chioma" is a facsimile, a "copy"; she's searching for the "real Chioma" in the Vex Network. That's the point, and I've already explained it. Saint-14 didn't "belong" because she considered him a "facsimile", a "copy" of the original Saint-14 who died, one pulled out of time. There is no hypocrisy there, so it wouldn't be an example of "bad writing".

You're making assumptions without objective proof. I would say it's poor writing when you have a character who gains the power to control the vex and build whatever she wants and yet her motivation for controlling the vex and wiping out current humanity is finding her lost lover? This doesn't make any sense since in past lore she seemed to only care about knowledge and power. Which was demonstrated in act 1 and 2 as well as veil containment and previous written lore. So then to change her character so that her lust for power is satiated and all she wants is her lover just feels like bad writing especially since lore wise, characters who come in contact with the darkness become more obsessed and corrupted. I get what their doing with the whole tragic misunderstood villain who gets a redemption arc, but it's also very played out in the destiny universe. I mean they did it with Caiatl, Eramis, Crow, Riven, The fallen, Mithrax, Savathun, Fikrul, and probably a handful of others.

What I stated above was based upon both the opening cinematic of this Act and how she treated the Chioma she had degaussed because she didn't fit the parameters of her search. Multiple things can be true at once. She will use the Vex to recreate the Golden Age, [b]and[/b] she wants to find Chioma Esi in the Vex Network. Furthermore, the methods she is using to pursue both are far from benevolent. She is not a one-note antagonist.