I feel like half of their positive persona is because they aren't a traditional company. They don't care and they are creative with marketing. Gamers are mad about launchers? Boom fix it. Despite the fact it will hurt their sales as it promotes other launchers business.
Same thing with Microtransactions, DLC, Expansions.
The positivity is worth the slight hit in sales as it eventually will benefit them. The long game.
My coding skills are quite rusty (please correct me if I am wrong) but I am pretty sure that if push comes to shove you can run Steam in the background, and pull data from it once you are logged in to display in Galaxy 2.0.
In the end it will be just a GUI that serves as a HUB, and launchers run like plugins in the background. Valve's cooperation just makes your life easier.
As developers, they have access to Steam's API. They don't really need steam. They have everything they need. Now if Valve got involved, they could do more and be better.