The UK example was more about their method of transitioning from private ownership to employee ownership, basically me going on a tangent to say that it isn't always all great. However the nature of the different types of business ownership is consistent everywhere, more or less.

• Private ownership - the business works for the owner(s).
• Employee ownership - the business works for the employee shareholders.
• Co-op - the business works for the co-op member shareholders.
• Publicly traded - the business works for the public shareholders. Additionally, the CEO is bound to this by law (both in US and UK, and most other places I imagine), not just their employment contract, and in practice this means the CEO must pursue profits because that's always what the vast majority of the stock market wants.

Valve is up there at private ownership, not employee ownership. Arguably employee or co-op ownership might be better, but I'm just happy it's not public.

Like you say, a co-op business in the game space would be interesting. Something like a mutual insurance company, where the customers also own shares in the business.