Your link shows new Macbooks were released less than six months ago and iMacs less than a year ago.
The only things there more than two years old are the MBP non-Retina, which is essentially an obsolete line, and the Mac pro, which Apple has never seemed massively invested in.
The only things there more than two years old are the MBP non-Retina, which is essentially an obsolete line, and the Mac pro, which Apple has never seemed massively invested in.