Valve is still surfing on the inertia of their initial software-based innovations, and is only continuing to cruise along by siphoning off others in their (lightly) curated market.
How much money is sitting in the coffers at Valve Software? What practical force prevents leadership from allocating just 1% of that pile of cash to something like TF3? It almost feels like we are being intentionally suffocated by our entertainment industry these days. It's the exact same story at Blizzard/Activision, EA, etc., but at least in those cases you can blame the publicly-traded aspect of the organizations.