Somewhat right, but mostly wrong.
You assume that next-gen companies are going to monetize games the same way they always have. That is constantly evolving, and we especially saw that last-gen. You went from games having an ARP of ~$50 for the Wii and ~$60 for the X360/PS3 to >$60 thanks to DLC, themes, avatars, and microtransactions.
So where does next gen go? More digitally-distributed content. This is where the X720/PS4 have a huge advantage over the previous generation, as they have an entire generation of lessons learned. Sony and MS have likely gathered billions of data points, and fleshed out many KPIs when it comes to designing the next generation interface, as well as online system. Such things can't simply be added to the 360/PS3, and that is why next gen is valuable.
So what am I talking about? The reality is that digitally-distributed content makes publishers more money. A LOT more money. Instead of making $30 on a $60 title that will not be available in 6 months to $45 on a $60 title, plus a 70% cut of DLC, plus a persistent retail store online that can constantly drive users to the experience. Castle Crashers is a good example of that. Its been out for >4 years on Xbox Live Arcade, but its still a top-five title in regards to annual sales, even excluding DLC. Furthermore, they're still charging $15 USD almost every day on it.
That is what the next-gen publisher is going to crave, which is something that the previous generation consoles did good at, but not great. Many X360s came with only a small amount of HD space, which meant many users couldn't download large libraries of content. We seemingly believe that Microsoft will include an HDD with every console, which will help significantly. Furthermore, we should see online penetration rise from ~70% to ~90% with next-gen consoles. What does that mean? Everyone wants online, and the new networks will be able to support it (which again means more money for publishers).
So it may be true that there are ~140 million consoles out there for this current generation (PS3/X360), but how many of them still work? 70%? How many of them are online? 70%, or so. How many of them actively seek out digital content for their games? 30%? In that scenario, you end up with a mere 20.6 million users that actively participate in becoming high-value gamers.
Next gen developers see that, and know that, and want far more users generating far more money. Imagine a world where 1 Call of Duty release will sell a few thousand copies every month at an ARP of $50 for not months, but years if not approaching a decade. Long-tail sales are the holy grail of gaming, and next-gen will help publishers reach that.
As for persuading consumers with this huge shift - I think Microsoft has the most brilliant idea with their $99 subscription-based Xbox. I believe that Microsoft will push this in the next generation, and if they do, will make the WiiU irrelevant overnight (and force Sony into a very disadvantageous situation if they cannot emulate it).
Why? Because you go from requiring $399 for the next-gen experience down to a paltry $199 or less. Not only this, you also force users to purchase a monthly online pass for content which repays Microsoft's huge loss-leading activity. Why does that matter? Because it means the said user is online, ensuring that their eyes are far more likely to download content for said games, increasing their ARP by very effective margins.
So in the whole scheme of things, publishers are going to have a huge incentive to push for the next generation, rather than continual catering to the 360 crowd. You're right in that they can port to it without a huge loss in fidelity, and that means that publishers won't have to take huge risks going forward, which gives them all the more reason to step up to next gen.
Back from the dead, I'm afraid.
