Hmm, that footnote was very hard to notice, so I was quick to point out these errors to the person who maintains the blog, only to get blocked by her on twitter. Not sure why go that far.
Because, if you're going to criticize the article, maybe go read everything there is to read? Because every one of your points was addressed somewhere in the article.
Furthermore, I am not sure why not write out the complete code, even if the author knew the code was not correct, even when pointed out, it would have been very trivial to initialize the variable.
Because the author made a stylistic choice to publish slightly incomplete code to get to the point faster (and pointed that out in a footnote, which was just as easy to spot as the "bug"). The point of the essay is not a perfectly executed C program, it's to demonstrate code disassembly and reverse engineering. More attention on perfect C code means less attention (reader attention and author attention alike) on the essential facts the author is trying to communicate.
In addition, I'm not an expert at this stuff, but it seems like initializing that variable would make the disassembly more complex and thus obfuscate the point just that much further.
The gist accompanying the article of the full source code contains the same bug. I'm not convinced it was a stylistic choice in the blog for a clearer explanation.
I would expect the full code to be correct/complete. This type of bug goes well beyond "I also make some assumptions in string handling that are considered gravely unsafe to use in a modern program, so please do not use this code in the real world." IMO.
The C code is literally the least interesting part of this essay. This bug, such as it is, does not matter. It is entirely and completely beside the point.
Regarding your last sentence. Reverse Engineering is a complex task, and obfuscation is but one of the many challenges a reverse engineer faces, granted malloc/free or stack variable and the example binary not being one of them.
The title of the essay starts with "A Gentle Primer". Think less "this is a complex and deep thing that is hard to understand" and more "check out this neat thing you can do with computers! computers are awesome!"
