As I explain in the sister post, my software contains years of research. It's not the code that I'm keeping secret, it's my hundreds of hours of testing and researching and experimenting to find out how certain inner-system mechanics work. I want to help people achieve these, but I like being the reference for this.
There are already people that have stolen (early versions of) my source code (and I mean that literally) and are selling it for profit: http://www.vistabootpro.org/
I don't want people to be able to do anything like this. I love the control that I have, and yes, it is a great responsibility. I could abuse this control and charge exorbitant rates for the software and technology, but I don't. While I'm not looking to make money off of my knowledge and prefer to distribute these tools for free, it doesn't mean I don't mind others making money off of MY hard work and research. Whether it's a big company or a small-time get-rich-quick jerk doing the capitalization on my efforts, I really don't want it.
I guess it also does have to do with acknowledgement: I want people to know that someone worked hard and is giving this away for free. The minute I give up the source code, the ideas are let loose and anyone can monetize/abuse them. In a way, giving up this measure of control would dilute the value of it.
tl;dr I don't want anyone getting rewarded (money or attribution) for my hard work and research. Yes, it is a selfish principle, but I think I'm allowed that much given that everything else I'm doing is selfless...