How do you know that the games are usually almost complete?

They get cash from Microsoft which can help towards development, so it's not a waste of money, it's very helpful for getting the game completed.

Valve do multiple projects at once

Exactly, totally makes the speculation over money lost more invalid

Of course it's silly to say no money is lost, but reliable data isn't there to show how much of an impact it actually makes.

Used-game market is very damaging because it is on the high-street, it is seen as legitimate business and it is a near 100% lost sale guaranteed.

I don't think I believe this. If you are pirating it then there is probably a barrier stopping you from buying it, be it financial, be it that you don't feel the software is worth the money, or you don't feel that the services with a legitimate copy are worth it.

If pirates don't pirate, they wouldn't buy the game. I believe that too, but it's a belief, there isn't data there (much like I believe there is still incentive for pirates to pay for the game, piracy techniques and cracks aren't perfect and lose a lot of the services a game gives).

DOTA 2 has been supplemented with Source 2 technology in the form of in-engine tools, something that Source engine didn't have. The Source engine arch is also incredibly modular, the dependency set is very loose which is why it has lasted so long, there is no good reason to throw out the old engine when you can just…

In a non-creepy way, that's the best thing about PC gaming. Means people can make the game their way.

"money that will be lost due to pirating"

Doing it the "proper" way totally cramped up my hand! I don't use my middle-finger, I only use my index finger to move it. Everything else I had right, maybe my hands are too big?

An engine is not defined by what graphics API it uses. These days a graphics API is abstracted to the point that it shouldn't be an influencing factor in engine design.

People usually factor in Windows into the cost of a PC, which can range from $15 right up to $160 in cost. SteamOS is a free operating system so the machines will come with it.

Console hardware doesn't magically improve over time, games improve on console graphically as new research is made into rendering techniques and the quality is actually dropped on consoles (Games will drop to 30 FPS and start rendering at 600p upscaled).

This current generation started off akin in power to mid-range PCs, the last generation were akin to very high end PCs at launch, so already it's not difficult to match console power.

The Vulkan API is critical to reducing the overhead of graphics performance, then you have SteamOS itself which is in Valve's control so a lot of the fluff in Linux can be removed or streamlined by Valve to make it more game oriented.

A lot of people get PC for the exclusives and community.

Thing with Source 2 is that it's still Source, just that the tools have been built into the engine (yay finally), so it's not actually that much of a big deal.

Current generation are not hard to beat with power. $400 is achievable without being a manufacturer, less is definitely achievable if you have direct access to supplies.