I played a lot of Sierra games in the 80s. I grew away from computers for a while and at some point in the 90s, Sierra sold out. They were basically drug through the mud, canned all its devs and became a brand rather than a software company. Sierra was also the first publisher of Half Life.

I was reading the history of Sierra there other night on Wikipedia and was sad because so many great games came out of that company and most were memorable. Hard to see that in any gaming these days

Back to my point, I started thinking that Valve saw what happened to Sierra and Newell decided fairly early on that they would be a software company and publisher and not sell out to a third party or take the company into the market. Pure speculation on my part, but they got their start sort of at the end of life of a bunch of 80s software companies. EA is certainly a shadow of what it was but it's still around at least as a brand.