... and there is one thing you are not considering, that some people who have the know-how and are professionals in their respective fields, just may be getting paid much, much more doing what they are currently doing, and/or have a much secure job, and/or doing something much more rewarding to them, than working for a gaming company, but do game mods as a hobby.
Possibly, but if I were in that field and I had a choice of either:
A) Writing programs for systems that were for corporations/busineses that paid me really really well
or
B) Writing programs for a games developer (that I love and otherwise would be doing in my spare time) and just getting paid really well
There wouldn't be much of an option for me. Different strokes for differnt folks though eh?
I'm guessing those that fall into that category would be far and few between though.