> They would have been better off building a war chest and pulling a Valve (though I'm sure they'd hate hearing it that way)

Isn't that exactly what they were trying to do with the Epic Game Store?

Steam is the thing that has made Valve successful. They were great as a game company, but as you said, the games don't last. Steam does, and I don't think Valve would be that successful in a business sense without it.