Last gen some things have changed. Devs have focussed more on the console market because there was less piracy there and the market was just bigger. When the x360 & ps3 released they also had very strong hardware that catered the gamer and dev alike. We're now 8 years later and hardware has improved a lot.
The consoles could have kept it's dominance in a way, if they made next gen consoles that were worth something. But releasing consoles with top of the line hardware is expensive, it's not like with the pc you can manage your upgrades when price/performance is at its best.
Anyway you put it, a true gamer is a graphics whore and when the pc is going to show off massive progress over the consoles, even console gamers will become frustrated. The pc can also cater the needs of console gamer today, even more with the steam machine. Virtual reality will make the difference even worse, because vr needs high framerates and high resolutions, something the next gen consoles struggle with and they just got released
Steam machine and pc will be on the rise and nintendo seems to be making a new console too, much more powerfull than the ps4 & x1.
Burn the heretic, kill the mutant, purge the ps4 & the xboxone... listen to the video and hear the voice of the pc master race