Here's why (I think) PC's have seen their best days as a gaming platform, and why consoles (possibly) are the inheritors of the once proud PC gaming domain:
Benefit to Users
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1. Level playing field.
2. Fewer or NO Cheaters on consoles.
3. No high server costs. (don't cry to me about $50 annually for XBL. that's cheap for what you get. Have you priced a high-end gaming server lately?
4. No community organization(recruiting)and management(drama mediation.)*Paying for the server is one thing, populating it regularly is a whole separate issue.*
5. No separate voice server. (teamspeak)
6. No game choking anti-cheat software (punkbuster)
7. No self matchmaking. (trying to find a worthy clan to play with)
8. No ridiculously high upgrade costs for the life cycle of the
console. (some PC enthusiasts I know are so addicted to PC hardware they have to upgrade monthly with stuff they don't even use or know how to use.)
9. Split-screen.
10. Big screen.
11. Sofa.
12. No crumbs in your keyboard.
13. No hemorrhoids.
14. No lame home office isolation.
Benefit to Devs and Publishers
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1. Consoles are more affordable and accessible to the mainstream. (resulting in more money for games which results in more game sales.)
2. No guess work for hardware requirements.
3. Minimal customer support.
4. Higher total sales thanks to rentals.
5. Captive marketing.
6. Lower costs overall.
Even retailers would probably prefer not to have to carry PC games. They aren't packaged as securely, and they probably suffer a lot of grief and damaged product due to compatibility issues and the like.
If I missed any please feel free to add to this list. Or totally counter it. Debate is healthy.