Why not? It worked for the XBox. Microsoft worked up a multi-billion dollar loss leader for years and bought up some of the best game studios so they'd write games for the XBox. The division finally started turning a profit in 2008, and it'll probably take years more to pay off the loss leader built up over the previous seven years.
However, give Microsoft credit for taking the long view, they're now firmly established, and even respected, in the gaming industry.