This is an honest question: Having been in IT and software development for over a decade, I have never encountered a problem that required me to look at the source code. As such, I've never really understood the open source movement. I can't imagine a scenario where the software I am using, the same software used by hundreds of thousands of others, would be broken to the point where I had to go into the source and fi…
I started working with Microsoft platforms professionally at age 15 or so. I worked for Microsoft as a software developer doing integration work on Visual Studio. More than ten years after I first wrote a line of Visual Basic, I wish I could never link against a closed library ever again. Using software is different than building software. When you're using most software for it's primary function, it's a well worn pa…
It's very empowering to read the source code because one can learn a lot.
A few more things to add from your points:
To work-around a software, sometime I have to understand how it works internally and given the source code, I don't have to spend a lot of time to reverse-engineer it.
Having said that, sometime the customers do care if it's my fault or IBM faults if we stated clearly in the deliverable that "hey, we're using IBM WebSphere for this...". They would give IBM some time to fix it, or ask us if we can work-around it, or they would bend certain requirements (i.e.: work-around the requirements, not the code).
This is why sometimes, probably a dying trend given the quality of open source software, an outsource project chose software based on the company behind it.