Only if your intent is to misuse or misappropriate that code. Is that what you're advocating? Because if you think it is OK for someone to disassemble part of Microsoft Windows, then port that code directly into Linux without doing so illegally, you haven't a clue as to what you're talking about. His original statement - Most commercial programs, like those made by Microsoft, keep their source code secret - remains correct.
I didn't say it was legal.