Make money from double dipping.
These companies can't afford anymore to spend $600 to make a console and sell it for $600 so the specs can hold up and in the hope that everything goes smooth until the next gen starts 6-8 years later. If a major disaster or crash happens during that time, and people can no longer afford the $600 console at launch, or $500 price drop years later, these companies end up in major financial trouble.
By selling a console around $400 at launch, and actually making a small profit, while they are still at risk, that risk is greatly minimized by the console being $400 instead of $600. That just means more money left in the companies bank for an emergency.
This also allows the companies to gain more profits overall, and allows them to sell another mid gen refresh, making even more money, due to the fact that the hardware becomes outdated faster now due to the cheaper launch price and lower specs. All because they are playing it safe. The fact that it used to be normal to build things to last and keep them for extended periods of time, yet today things are built to break, and people are expected to, and some like to, buy updated things more often, makes this type of console cycle easier to swallow.
The rest of the points all fall into place, and are all byproducts of this, but making money is always #1. I would say 4k tv's #2 and PC #3.
