Perhaps because they view the people using the device as their primary (or perhaps only) customers? As opposed to a lot of other hardware manufacturers, where

Perhaps because they view the people using the device as their primary (or perhaps only) customers? As opposed to a lot of other hardware manufacturers, where the end-user is 'part of the ecosystem', along with advertisers, and other 3rd parties. Microsoft and Sony certainly look at Xbox end users (aka gamers) a bit differently than Valve does. They need to keep publishers and advertisers happy. Valve has one audience...others have three (maybe more!?).