- Last gen, almost every company lost money over the course of the generation. Maybe two or three came out ahead of where they were when the whole thing started. That info is available in public financial statements.
- More developers went out of business than any prior generation. Also a matter of public record. Many new devs sprung up, but few of them do console work, instead opting for the safer pastures of PC and mobile. And usually small-scale indie-type stuff.
- Japan, one of the historical three major console markets (and the only one where PCs are a non-factor), have lost interest entirely in console games. Also a matter of public record, see Media-Create or Famitsu data.
- Games cost more to make this generation than last. That needs no proof, I'd assume.
- The overall console market is smaller than it was last generation at this time. A big chunk of that is Nintendo fumbling out, but third parties made a ton of easy money on Nintendo last gen to offset HD console losses, and that isn't going to happen this time. On top of that, the Xbox One is not doing well at all. Every position (1st, 2nd, 3rd) has sold through fewer consoles than the same position last gen had at this time. Smaller market = lower potential software sales.
- Meanwhile PC and mobile sales are great, rising year over year, with considerably lower budgets to boot. It's a very attractive alternative.*