The HL3 memes don't even seem fair to use anymore. I don't even want to un-seriously make joke fun of them at this point. They are just genuinely doing so much for the community.
But overall Valve just seems straightforwardly less shitty towards the consumer than other major companies in their space, by a long shot.
Valve can be Valve because HL + Steam, in the same way that Google ~2010 could not be evil because search + ad revenue.
The difference is that Google IPO'd and took market capital, and Valve didn't.
Once public investors are onboard, you maximize profits or face lawsuits.
As the simplest example, they could have stamped HL3 on a third party game and made several millions of dollars with only a minor hit to their brand (in 5 years, "that bad HL").
In more realistic terms, they could have built proprietary, closed source emulation packages (they are funding a lot of development, apparently) to give themselves a unique advantage.
If they were a publicly traded company, they probably would be doing all these things.