I'd say
SEO is actually very straight forward, 95% of it is very basic and easy to undertsand, just not so easy today to implement so it's easy to stop or not see it through seeing as it is a continual process - some people would like to make you think it's harder than it is.
1/ Make sure your main keywords appear in you title tag & description tage and main page but do not be spammy and make sure each page on your site has unique content and title/description.
2/ Get backlinks from relative site which link to you with some of the main keywords in the link
3/ Get links from relative site that link to you 'in context' using your site name
4/ Make sure links are not just targetted at your homepage.
That is about it for the most part, if people are trying hard without success it is usually down to
1/ Poor quality content
2/ Poor quality inbound links
3/ Stopping
SEO work
I remember 5 years ago when I was really looking into
SEO and reading and testing that people were saying how they felt the results were less relative then, I think you will find that in return for what is a free service (Google) many average users are prepared to put up with some noise and for the most part get what they want.