I have no opinion about who's right or wrong on this, but the article does give multiple reasons to dislike the code -- calling it an "unportable hack" that "few people... will be able to fix when faced with problems", stating that it doesn't seem to have much value, and suggesting two simpler ways to achieve the same desired effect.

In my reading, the author doesn't even complain that it's a security issue, just that it will likely fail on systems with certain security measures. And the author never says it's bad simply because it's self-modifying; rather, that the self-modification is a "platform-specific reimplementation of a linker".