Well, that's because the article he linked talks about going much further than just flipping a stem. You do have to take the cap off the steering head, and you do have to adjust the tension properly. But you definitely are not dropping the forks and all that.

Also remember I'm not advocating that you flip this particular stem. It's too much angle. I'm advocating that you buy a shallower degree and try that, first in the positive direction. If you want to go further, try it negative.

The LBS comments are good ones too. You can't go wrong with a good bike shop helping you.