Nah, with modern intel cpus not improving as much as before from gen to gen, I think many people with decent quad-core 3-4 year old systems are likely okay. Take me for instance, I've got a Maximus IV Gene Z with 16Gb dominators and a 2500K running at 4.3Gz and I really have no issues with performance, neither in games nor anywhere else, granted I don't do any video editing or complex graphic design but still, I really don't need AMD or Nvidia or any other kind people to "help" me upgrade my system by burning my shit. I think I can easily get another year and a half out of it if no napalm applied to my PCI-E slot.
Yeah since Intel came out with Core M and pushed that IP over to desktops, I have only had two major upgrades to my systems, and one of them was because of the change in BIos types. I really didn't want to upgrade my dual xeon system but the new graphics cards just wouldn't boot up.