Here's the only part of the article that I really agree with: "Don't waste your time hating your job and doing it badly." That right there is the real reason why hating your shitty job only makes it worse: because you're wasting your time hating it, instead of looking for a way to either change it or quit.
As for the idea that "at the very least you'll make your days more pleasant with a positive attitude", I wish I could construct and program an army of little robots whose only task would be to kick the people who spout this crap in their shins.
If you subscribe to this "positive thinking will solve all your problems" mantra, I encourage you to watch this RSA Animation of a talk by Barbara Ehrenreich: http://y2u.be/u5um8QWWRvo
Finally, I'd like to answer the last question in the article. Did I enjoy this article? No, I didn't, because it had too much emphasis and I found that very annoying.