Employers by nature seek profit above all.

That's may be true for publicly traded companies, but for privately owned companies, that's not necessarily true, especially owner-operated businesses like LMG (I know he hired a CEO, but Linus seems to be very involved still). Profit is certainly a concern, and it needs to be a concern for the long-term viability of the company, but employers can be driven by something else. For example:

• Gamer's Nexus - seems largely motivated by integrity in tech journalism, and you can see it in how they spend their money (I doubt they turn a profit on prebuilt reviews, they're building a high quality anechoic chamber, etc)
• Valve - selling the Steam Deck at that price point was "painful," and they still have a very open work environment from what I understand; Gabe Newell seems more interested in being an independent PC platform (even going so far as building SteamOS) than just pumping out short-term returns (as an alternative, see EGS, Origin, etc that merely try to capture sales to avoid the store's cut without providing really any additional value)
• my previous employer - small business, made security hardware for businesses and military; my boss' stated goal was to save lives, and I think he did a good job sticking to that, at least until he essentially sold his stake in the business (coincidentally when I left)

LMG could absolutely fit that mold. He seems to still have a passion for the tech first, though he has been shilling his merch a lot harder over the last couple years, so maybe his mindset is changing.

My point is that companies don't necessarily seek profit above all else, but they do need to seek profit at some level to maintain the long-term viability of the company. That said, most companies do seek profit above all else, and you should absolutely have that be your default assumption, but leave room for owner-operated shops to actually care about their products and customers above profit.

Unions by nature seek improved wages and conditions for the employees above all.

Again, I disagree. Maybe unions start that way, but they operate like any other political entity where they largely want employees to keep paying the union dues, and the union management likely wants to increase their own salaries. So their focus is on doing something so they can convince members to increase their dues, and that something doesn't necessarily have to be in the best interests of the members, it only needs to be convincing enough that people will agree to the dues increase.

That said, unions are probably more likely to seek improved conditions for their employees than an employer, just make sure your union leadership is good so you don't get screwed over by nonsense. Some unions operate more like HOAs, where it's more of a power trip than an actual mutually-beneficial relationship.

What I see is an employer trying to keep his reputation use deceptive doublespeak to discourage unionization among his employees.

I see the same, but that's because when in doubt, I prefer to side with the weaker party. I still want to see more facts emerge before I start urging others to avoid LMG, I'm not going through that effort on a hunch.