Again, there's a difference between open source where what you're open sourcing is the CODE and open source where what you're open sourcing is the TECH and research. I'm not saying one shouldn't open source the tech, but I'm just saying I'm not that generous.
If I can download your program, I can learn your tech and your research if I'm willing to put in the effort. Don't naively think that "keeping it closed-source" keeps anything away from prying eyes except possibly your code comments. Most likely, if nobody steals your ideas, it's because they don't care, not because they can't.
I work on the ffmpeg project, which contains literally dozens of video and audio decoders for proprietary formats, many of which were based on nothing but symbol-less closed-source binaries. Not releasing code simply makes the job take an extra week or two.
The skill of the developers who have this expertise is staggering and should never be underestimated. One of them, for example, reverse-engineered a neural-network adaptive image resizer and created his own implementation -- generating bit-identical output -- in a mere 11hours. He then spent 2 weeks optimizing it to make it 4 times faster than the original, and published it -- which led to the original author (of the closed-source version) releasing his source.
I also work on the x264 project, which is literally covered in "tech" and "research" that's been open-sourced. Curiously none of our (usually much-inferior) proprietary competitors have ripped off our algorithms (and yes, I actively check for this). My guess, from talking from people in the business, is that they're so deathly afraid of the GPL that they aren't even allowed by their managers to look at our code.
The effort it would take to reverse engineer my code is the same as the effort it took me to reverse engineer the Windows code in the first place, to allow me to extend it in the way that I have. not against people putting in the effort and learning for themselves. I'm against people making a quick buck by downloading my source code and getting a ready-to-use framework to build on.
I have been approached by backup companies (for "universal restore"/"bare-metal restore") who wanted to license this tech for free and have had source code stolen and being resold by "competitors."
I think that should clear up my concerns.
EDIT:
Read your update, and completely concur. There are people in the open source world that can do crazy, impressive, and amazing things. People like that, I can and do respect. I've shared my code with a few others before, and someone like that I wouldn't hesitate to say yes to. But to let it out in the wild..... it's just too hard for me.
If I can download your program, I can learn your tech and your research if I'm willing to put in the effort. Don't naively think that "keeping it closed-source" keeps anything away from prying eyes except possibly your code comments. Most likely, if nobody steals your ideas, it's because they don't care, not because they can't.
I work on the ffmpeg project, which contains literally dozens of video and audio decoders for proprietary formats, many of which were based on nothing but symbol-less closed-source binaries. Not releasing code simply makes the job take an extra week or two.
The skill of the developers who have this expertise is staggering and should never be underestimated. One of them, for example, reverse-engineered a neural-network adaptive image resizer and created his own implementation -- generating bit-identical output -- in a mere 11 hours. He then spent 2 weeks optimizing it to make it 4 times faster than the original, and published it -- which led to the original author (of the closed-source version) releasing his source.
I also work on the x264 project, which is literally covered in "tech" and "research" that's been open-sourced. Curiously none of our (usually much-inferior) proprietary competitors have ripped off our algorithms (and yes, I actively check for this). My guess, from talking from people in the business, is that they're so deathly afraid of the GPL that they aren't even allowed by their managers to look at our code.