Old Sites = more links because webmasters are lazy to take them down
New Sites = webmasters who refuse to add links due to time and effort - too many requests
Webmasters are just plain tired of adding links where in the past they were more likely to be willing to add. I'm not saying that links don't work...they do. I'm just saying that the older sites have too much advantage because back in the day it was easier to get a link...they live off the past links.
Truth is, Google is not dated. There are many SEOs out there that are dated in their knowledge.
As WebmasterWorld moderator, martinibuster, said:
The only thing dated is webmaster conception of the algo. It has been changing a lot, including recognizing that citations come in social sharing scenarios, that citations hidden in JS and other technologies are being digged out and many other changes created just to the citation part of the algo. Then there's the part about content, what parts of content are more valuable. The list goes on and on.
I can't put it any better.
SEO conception of Google's reach and ability when it comes to their algorithms is dated. Google's algorithm continuously is changing, more often for the better. You can argue with that of course.
Forum discussion at WebmasterWorld.
Image credit from ShutterStock of old man sitting.