Earlier quoted context omitted.
I'm not anti SEO because it's unregulated or unstable. I'm anti-SEO because it seeks to subvert the search engine's mission (return the most useful results for the searcher* ) to something more akin to advertising (return the results that the person paying for SEO wants). It pollutes and subverts the web experience for everyone. It's not the practices that are the problem, it's the whole idea. [*]OK so I acknowledge…
Many SEO techniques are in line with the user's best interest. Sitemaps, Keywords, accessibility (clean source code) etc. help Google to understand the content of your page better. That's the reason why people like Matt Cutts exist. Of course, much of SEO IS dirty, and I am not sure if there is serious movement of "ethical SEO".
Competing for a ranking is pretty much a zero-sum game because no matter how much money you sink into it, only one can come out on top.
Compare and contrast with actually building stuff that makes people's lives better: there's still some competition, and winners and losers, but it's usually not a zero-sum game at all.