Did you read the actual letter? I ask becasue it's not included in the NYT article, so I'm not sure whether your complaints about political correctness and your comparison with Christian values stem from not knowing the contents of the letter or something else.
There are basically three problems the open letter highlights and asks the leadership to address. They're wrapped in polite, corporate-appropriate language, but I'll express them here in plain, blunt, non-PC words:
- SpaceX is supposed to be bigger than just Elon Musk. Elon's shitposting on social media is harming the whole company, and the employees will end up suffering because Elon keeps putting his ego before the company.
- The so-called leadership, as it happens all too often, keeps talking the talk, but they don't walk the walk. They say they care about making SpaceX a great place to work, but that's just bullshit as long as they turn a blind eye to the toxic fuckery at SpaceX.
- The company policies are bullshit. Using words like "asshole" to sound cool and non-PC does not replace having an actual policy. "Zero tolerance" means fuck-all if you selectively tolerate stuff, and "no-asshole policy" is either too vague or isn't enforced.
Basically, it boils down to being sick of the toxic corporate LARPing you see in a certain kind of techbro companies, where suits pretend to be cool and down with the techies by using words like "asshole" to show how they value "straight talk" and therefore you can totally trust them not to fuck you over.
I hope that was non-PC enough to help explain what the letter says, for anyone who hasn't actually read it.
On the off chance that you did read the letter and you really decided that it's no different from "a bunch of hyper fundamentalist evangelical Christian SpaceX employees" demanding that their CEO behave according to their values, then I would like to point out two details you might have overlooked:
1. That would be perfectly understandable if the company itself claimed to hold and represent those values. If the employees of the hypothetical Every-Zygote-Is-Sacred LLC wrote a letter complaining about how their CEO kept tweeting about how much they loved and supported Planned Parenthood, then they would have a point, regardless of whether you or I were pro- or anti-abortion.
2. Regardless of what company policies say about the company values, many companies have a policies about social media, along the lines of "don't tweet anything that would negatively affect the company, not even on your personal account". People can, and do, get fired for breaking that policy. Complaining about how the CEO of the company keeps blatantly breaking that policy and actively harming the company in the process might be naive, but it's certainly understandable.
In conclusion: yeah, I think it's right and acceptable for SpaceX employees to complain about the unprecedented level of toxicity from their CEO.
EDIT: I accidentally a word in the last paragraph.