I agree with the gist of what you are saying wholeheartedly. Always be prepared to be thrown under the bus by your employer, no matter how unlikely it seems... but that isn't really the message of the original blog post beyond the possibility space of the headline.

The actual contents are almost the opposite, the blog poster stayed around in their role for an entire year while letting their employer know they were unhappy.

I'm all for professionalism when leaving a job. For any full-time position I've held I've always followed the 2 week notice standard as a minimum and have even done part-time work past the 2 week period in a couple of special cases where I understood the burden on the company I was leaving was more than a 2 week transition could handle.

... but I don't see how it counts as being ready to quit at any time if that quitting is the result of the company not being able to fix a job situation you've told them isn't working out for you over the course of an entire year.