Sure you can go as deep as you want with anything.
For a major company or organization thats fine. Go balls deep.
For a small home business or game developer. All you really need to do is this. What matters is results v. effort (When working at that scale)
I follow this method and I am quite successful at affiliate marketing, was able to quit my day job.
I respect your opinion, do things however you would like. SEO is def a deep subject. But I like to melt things down to practicality