What is closer to the truth is that nowadays "average" technical people are way more abundant than ever, mainly because there are ever more and better learning sources (books, ebooks, conferences, video tutorials, chats, forums, certification courses, crappy 2-year colleges and good universities, fancy IDEs, super high level programming languages, frameworks and libraries for everything, etc.) The learning curve is not as hard as it used to be, if you want to be an "average" technical guy.
And it's just basic economics that people (and entities composed of people, such as companies) don't like to pay a lot for something which is extremely abundant and available in their area (logically). This is because when humans are in the process of valuing things they're affected by a mixture of need, personal preference, the scarcity of the things in question, and the moment in time when this process is taking place.
I've been a "pawn" "low life" "technical monkey" developer for a while, and I actually began working as a developer from the start with a secondary hidden purpose of studying the ways companies act (because I was already an economics nerd before becoming a developer), and this is the usual result of my observations (plus studying the history of other companies):
- Technical Monkeys with NO additional nontechnical skills: They're like the average rock drummer who can keep a beat but other than that is not very useful. They will always earn a lower wage, because there's just too many of them out there: they're not especial. Wage is just another price, remember.
- REALLY GOOD Technical Monkeys with NO additional nontechnical skills: They are exceptionally awesome and productive, and will get paid accordingly, unless they work for a really stupid boss. They're like the really good session drummer that records albums for all kinds of artists, and as a hobby breaks world records for faster drum fills, longest drum solo, etc. He has no other skills but he's a absolute beast at what he does.
- And then there are those Technical Monkeys who are good (though maybe not the best) at the technical stuff AND have really good business ideas i.e. better management ideas than their bosses do. So they can manage teams AND they can speak technical monkey. They're the Phil Collins. They will either earn a good wage or start their own company.