I never understood this claims, the only time consoles did a big jump was in the ps360 generation when shader become available.
Console have always been about delivering the highest graphical power per dollar, not about the highest graphics, PC has the lead there but also has a the lowest graphical power per dollar. If you take ps1 and ps2 as example, since those were dedicated machines the developers achieved outstanding results because the could optimise in a why that is not posible on PC. Also don't take the games that come out at the start of a generation as a point of comparison, they are alway terrible, just take a sample from each generation.
About the new consoles being .5 versions more, that is absurd, the ps3 has 256 MB of ram, last time I saw a PR with that ram was in 2001-2, today the ps4 has more memory that most current PC, event if the CPU and GPGPU are not state of the art they will output some great stuff because they are dedicated hardware.