A very interesting Google Groups thread has many bloggers, including SEO Buzz Box, DaveN, and Search Engine Journal voicing their reactions.
The background is that the webmaster of AlkenMRS.com realized that his 10+ year old site had been delisted from Google. With help from his friends, he addressed what he thought were technical issues related to his site. But even so, his site was not reindexed and the Google crawler had never come.
Adam Lasnik of Google explains that his site might have been the problem after all:
Imagine this scenario. You walk into a store and some guy -- surprisingly the owner -- grabs you by the shoulder."How'd you like some beer? Oh, hey, we also sell coffee. Hmm... you don't want something to drink? We specialize in air purifiers, too! And you know what... after you drink some beer next to your new air purifier, I bet you could use a date, right? No, no, not the eating kind... I'm talking a really nice lady! And if she ends up stealing your identity, well, no problem! I sell Identity Theft protection services... and... wait! Wait...come back!!!"
How much would you trust that guy? Or his store? Sure, he may have small leaflets on a zillion topics, but he's not an expert in any.
He then mentioned that site owners need to put that into perspective online -- because it's no different.
If you, as an independent observer, came across such a store online, would you trust it anymore? If not, why should Google see this as an important and relevant site?
Oops. So his site has, as Loren Baker put it, a "lack of quality, focus and trust." Most importantly, as Dave Naylor points out, the site was Made for AdSense. Essentially, Google is looking for relevancy and nothing but. Otherwise, the site has no value to visitors and won't be crawled.
Forum discussion continues at Google Groups.