Most likely, there is no major competition in the market, and PC sales on the whole have slowed considerably. A modern 6800K processor is as close as you'll come to a leap forward, but it's $1100 Canadian and requires a similarly expensive motherboard + memory. Same with similar chips.
Meanwhile the cheapest system on the market is as fast as a moderately high-grade enthusiast computer from 2010 and probably has reasonable 3D graphics onboard, with a SSD drive it will feel quite snappy.
So, a) not a lot of market demand for faster systems, b) lots of tablets and game consoles for entertainment out there, c) moderately faster systems exist but cost keeps them low-volume, d) very low-percentage demand for faster computers - definitely less than 1% that will pay a premium for it, e) the majority of gamers are young-ish and they play largely twitch games even on PCs which are more GPU limited than CPU limited.