Interesting perspective but I have to say there are quite a few companies working the whole "open source the code, charge for consulting, etc." thing. Just in data alone, Cloudera, Data Stax, Basho, 10gen and Hortonworks come to mind.
My point is that thousands of people get paid to work on open source projects. The project might not be their original creation but they still get to give back by producing something that everyone can use. Isn't that really the point anyway?
FIWI, I have personally not heard of a single one of those companies.
To continue the OP's concept, these are likely companies with employee counts in the single or double digits, whereas closed source companies have employees in the 5-6 digit ranges, reinforcing the "I'm not smart enough to get paid writing open source" concept the OP presented.
The problem with consulting is that you first have to have a product. That can take a lot of time and money to produce. Then, if you start consulting, it's all about billable hours. Hours spent fooling around making the product better may not translate, at all, into more money for the company.
This business model is fairly popular in education. We have tons of open source projects where we COULD run it for free, but sometime we pay for hosting, or consulting, or customization. It seems to work well too.
My point is that thousands of people get paid to work on open source projects. The project might not be their original creation but they still get to give back by producing something that everyone can use. Isn't that really the point anyway?
EDIT: added a missing 'not'