Again, the article makes no mention of proper color management. In a color managed workflow, the gamma setting makes no difference to what displays on screen. Whatever the setting is compensated in the profile.
What does matter, however, is that forcing a display into non-native behavior is never a good idea. And it's not even necessary, unless you care how it looks without color management (I don't).
For color management purposes, monitor calibration doesn't require a colorimeter. What you need to do is set the white point luminance and temperature, and this should be done in the monitor's hardware anyway. A hardware calibrator will do it of course, but it can also be done in the monitor's OSD menu. This is the user defined part. Luminance is critical, but temperature can be left at native if desired. Gamma should be left at native (it just happens to be close to 2.2).
Then you need to make a profile, a full description of the monitor in whatever state the calibration leaves it, using a colorimeter. That's the color management part (which the article ignores). A color managed application doesn't even know about the calibration, it doesn't need to. It just uses the profile.