I don't really have a say since I don't buy nor sell software. As a technical guy, I may have an influence, but usually, finance decides and not always the way I'd like.
That being said, I highly value having access to the source code, even under a restrictive license. The source code is the best documentation, it doesn't lie. Also being able to make small changes, recompile with different libraries, etc... but for me, the "documentation" aspect is the most important. I don't do security, but I guess being able to audit the code is a good thing too.
For me, open source goes beyond the "freedom" aspect. Also, AFAIK, most commercial game engines are "source available" too.
That being said, I highly value having access to the source code, even under a restrictive license. The source code is the best documentation, it doesn't lie. Also being able to make small changes, recompile with different libraries, etc... but for me, the "documentation" aspect is the most important. I don't do security, but I guess being able to audit the code is a good thing too.
For me, open source goes beyond the "freedom" aspect. Also, AFAIK, most commercial game engines are "source available" too.