This is the reason many SEO companies have rebranded as content marketers recently.

Content marketing is a relatively easy sell, and it's almost the entirety of ongoing SEO work (as opposed to the technical improvements, which obviously you can't complete over and over again!).

Few businesses are interested in where the content comes from, the research that goes into setting it up, so it's content marketing for most of the larger companies. I like the broad skillset 'SEO' implies, though, so I thought I'd highlight that.

EDIT: Also I suspect that if you're on Hacker News, you'll be more likely to have a much more technical skillset that fetches a higher price in other niches than SEO. There is, of course, more to the world than marketing!

Hopefully the links and general tone get some people interested though.