How come the "console killers" of 2013 like the Core i3 + 750 Ti or the A10-5800K & Radeon HD 7660D APU come to a crawl...

APUs are amazing and got me interested in GPU programming. They are excellent learner chips as you try to balance CPU over clocking with the GPU overclocking. They are dirt cheap, and can be made to do multimonitor setups with a VM stupid easy.

Throw a dedicated GPU on it if you need more performance for games and get higher performing bulldozer cores that come close to an 8350 in frame timings.

Or leave it as is and play around with it in a lab.

Console ports are lower than low detail settings and still run at shit res/fps.

That system probably handles the same games at lower settings, just like a PS4