I've always found it is easier to understand servant leadership as the opposite end of the spectrum from autocratic leadership: Is the leader primarily concerned about growing their own power/success, or growing the power/success of those who work for them?
There is a lot of middle ground between those two extremes, but without that contrast in mind, you can easily lose track of what the terms mean. The article does a decent job of trying to find a healthier middle ground, IMO.