Disparage not that which you do not understand.
The ultimate search engine would be ungameable, and SEO would be a waste of time because it would accomplish nothing. To the degree that SEO works at all, it is a bad thing.
SEO isn't what you think it is, yet you continue to paint all of SEO with your broad brush. Stop.
[1] (pdf) - https://static.googleusercontent.com/external_content/untrus...
White hat is not exploiting the rules of a game, it is following the rules. Proper SEO according to G is doing everything you can to make your site interact well with crawlers. That's akin to following directions when applying for a job, or following the rules when playing a sport. You can't be considered for the job if you don't apply properly, and you'll soon be disqualified if you ignore the rules of a sport. Same with search: if your site doesn't comply with a search engine's standards for crawling, you won't have the opportunity to be ranked fairly.
That's one of the first things I think about when I look at a site from a SEO perspective: can the bots easily digest this site.
I'm not saying that's where we are -- But that's hopefully the end-goal
Or your definition of "SEO'd" is leaning more to manipulative/sleazy.
In your example about the spectacle cases, would the other site being an affiliate make a (huge) difference? If Google punishes companies that have more than one website, people would shift to affiliates or try to hide they own the websites in other ways. In a way I feel multiple McDonalds in one city is perfectly possible. However, there needs to be a balance between the "best" websites (be they from the same owner or not) and diversity of the results (a query deserves diversity).
[1] http://www.codinghorror.com/blog/2008/10/the-importance-of-s... "We knew from the outset that Google would be a big part of our traffic, and I wanted us to rank highly in Google"
[2] http://www.mattcutts.com/blog/pagerank-sculpting/ "In the same way that Google trusts sites less when they link to spammy sites or bad neighborhoods, parts of our system encourage links to good sites."
[3] http://support.google.com/webmasters/bin/answer.py?hl=en&ans...