Actually, most of the software engineering industry makes money from selling their services to build new software, or maintaining existing software that was previously built in the same way.
The question of whether the software is then shrink-wrapped and sold for money is irrelevant. As a Ruby on Rails developer, I couldn't care less what my clients do with the applications I build them (except, of course, within the context of building them an application that better meets their needs). And the fact that Ruby on Rails is open source makes no difference to that - except, perhaps, in that it allows me to work solo and so not have to deal with a large team of incompetent people in my daily work.
Actual software licences are a very small market, most of it owned by giants like Microsoft and Apple.
Daniel