"What Would VALVe Do?" is a rhetorical question that one asks a video game company. It questions whether or not a course of action that a video game company is or will be taking is something that VALVe - a popular video game company that many gamers believe does everything right - would do.
WWVD is usually a chastising remark, meant to rebuke a company for a bad decision.
Come on, Capcom. You took the horror out of Resident Evil 5 and put in just pure action. I mean, What Would Valve Do?
Why do we have to pay so much for DLC? Why not include it in the game, or as a free update? What Would Valve Do?
Meaning "the business", de_Biz refers to the Video Game Industry. It could also refer to Valve Corporation.
The term is a reference to the naming system of maps in games created by Valve, particularly Counter-Strike. For example, de_Dust has the prefix "de_" meaning "DEathmatch" and denotes that the map is designed for the deathmatch gametype.