That’s no excuse. It’s their job as the writers of this scene and the heads of the game in general to make sure that the texts which make it into the game have a certain level of polish. People might disagree about the artistic merit of their writing, but things like grammar and spelling are non-negotiable, and that’s their view on the matter as well: the event submission guide makes a point to say that everything must be in American English, and Wsan in his blurb on writing mentions that Savin is a stickler for grammar.
Moreover, “I’m not a native” has no meaning on its own. If you aren’t a native English speaker, you can be in one of two situations. The first is if you’re fluent. In this case, you’re on the same level as a native speaker, and should be treated accordingly. If a native speaker comes to you and says, “This isn’t how I would’ve written it,” you are wholly justified in replying, “But that’s how I want to write it,” because your opinion on style etc. is just as valid as a native’s. In return, you must be held to the same standards as a native. The other situation is if you’re still learning English. In this case, you forfeit every right to dismiss criticism. If you’re learning, and a native speaker says, “This isn’t how I would’ve written it,” you cannot simply disagree and move on. If you’re a learner, then natives know better than you, and therefore you must listen if they ever criticize your style, word usage, etc. This is why “not being a native speaker” is meaningless: if you are offering a product, a written work like this, and you want your opinion to be regarded as equally valid to that of a native speaker’s, you must agree to be judged as a native speaker.