I would be shocked that low revenue is the reason why Sony is pulling back from PC. I rather suspect it's optics tied to brand value rather than purely dollar value from a second platform

The PC version of every single Sony title runs better than on original hardware. The reasons for this are numerous, but it looks pretty bad for hardware sales if the software you design, running on the hardware you designed is the inferior experience.

On top of that, it's a cold reality that piracy is simply easier on PC than console. The numbers here are probably not enough to matter for purely accounting reasons, but execs like it if that number goes down.