The concept of Authoritarianism? Why is it subjective?

I don't quite understand how Authoritarianism is so subjective. We have bosses, governments, reddit mods/admins, parents, etc relish in Authoritarian styles... but some people will deny its happening. Presiden Trump is quite possibly one of the most Authoritarian world leaders in the past 20 years yet people will say he is not Authoritarian or they will say he's just doing "what's right'. How is this concept so divisive even though you can literally point to Authoritarian leadership style and easily outline why.