There are two reasons for this. The first is that the 1/10th-as-good people shouldn't even have jobs. Their cubicle, chair, and the electricity to heat their work area are not worth paying for. But, good programmers are nearly impossible to hire, and you need someone to sit around and look busy while they are on vacation. Hence, bad programmers that are not worth paying for become worth paying for ... not to write computer programs, but to look like they're writing computer programs. Naturally they open an IDE and pretend to work, and may even create an app once in a while. But that's not programming, that's chair warming combined with some code monkeying. (Most 100,000 LOC "applications" created by people like this could be rewritten as five lines of Perl in fifteen minutes. I know because I've done it.)

The second great equalizer is the corporate world itself. Drawing from my own experience, 90% of the work done there is unnecessary. If Team A can't give me an API for their app that works, I have to redo their work. So now two people wrote that API. If the sysadmins can't figure out how to "yum install gcc", I have to install my own mini Linux distribution in my homedir. So now two people are the sysadmin. This all takes time and does not actually result in real work being done. Combine this with broken tools like Windows and Exchange, and your entire week is suddenly gone with nothing to show for it. (But that's OK, nobody expects anything.) If your actual job was to program computers, then you would be 10x as productive. But since your job actually is to redo other people's work, it's hard to be productive. Then there are other issues, like how nobody at a big company can read or write, so even the simplest problems have to be resolved with phone calls. Don't get me started on being able to read code...

So this is why people don't get paid 10x as much. The people that know that the work they're supposed to build on is inadequate for actually doing that spend that "9x time" redoing that work so that they can actually build on it. Or they have meetings.

At the end of the day, the guy who didn't write any code and just read Facebook all day is actually the productive one. At least he didn't make any work for anyone else.

(I should also mention that a lot of productivity comes from thinking beyond the current problem. The "YAGNI" attitude that is so popular these days is the cause of a lot of problems. Complex problems are really just very special one-offs of a more general but simpler problem. Solving the complex problem today leaves you with nothing for solving a very similar problem tomorrow, killing your productivity. Imagine the world before logic gates -- 10 transistors just to output 1 if the two inputs were 1? Imagine the world before programmable computers -- 100 electrical engineers working for a few years just to calculate a few prime numbers? Any problem is hard if you want it to be. "Professional programmers" want everything to be hard, so they feel like they are earning their money. They then code accordingly. And that is the real problem.)