OutrageousEmu said:
Even if you accounted for that, PC sales they wouldn't scratch console levels in most cases.
Take Black Ops, best selling game of last year. On 360, 12.52 Million copies. On Ps3, 10.08 Million copies. On PC, 1.12 Million copies. Even if you doubled that figure, rounding out that 48% to 50%, it wouldn't equal one quarter of the less successful console version of Black Ops.
I don't like to use Black ops as an example since it's the kind of game that attracts the kind of people who would want to pirate it, no offense. Working in game retail you notice that the people who try to steal them tend to have similar tastes.
You said it was "incredibly low", which 21 million discrepancy is not. It would actually be better to take into account the number of users with PC games, since those numbers tend to speak truer than sales since digital services, like steam, don't require repurchase when a game is uninstalled and there being a lack of a used market. A lot of people will re-buy console games for various reasons, lost, stolen, damaged, defective etc.
Steam, being a PC platform, has an average peak of 3.1 million users daily and there are a total of more than 30 million
ACTIVE steam accounts.
http://store.steampowered.com/stats/
http://www.rockpapershotgun.com/2010/10/18/thirty-million-steam-accounts/
Xbox live has anywhere between 2-2.5 million concurrent users. http://www.escapistmagazine.com/news/view/96096-XBox-Live-Hits-2-Million-Concurrent-Users
There are roughly 30 million Xbox live accounts total, but as to if that includes or excludes banned accounts they don't say. You can also easily make an Xbox live account and own no games, whereas you can't do that with Steam (well you could, but there would be no point in making one since you wouldn't be doing anything).
Considering how many people are playing something on steam everyday, I wouldn't write it off as "dying", and this is not taking into account other services. It wont die because all games are made on PC's using similar hardware used in PC gaming, as long as that hardware exists, there will always be a demand for the games.
Edit: I would also like to mention that console games have less "risk" in the sense that if you buy it, and get tired of it, you can trade it in. PC games, you buy it and get tired of it, tough shit.