Since I'm discussing this with you I obviously don't mean that, do I? I am also specifying that this is generally descriptive and not proscriptive. People have tendencies, leanings. It's a general behavioral shorthand, which can change over time and experience.
Because it is a useful shorthand. "Donblas the Justice Bringer - LG" Gives me enough information as a reference until I need or desire further detail. Much like "Calastia; Kingdom (King Virduk) - LE" can be a useful shorthand. Much in the same way as "Orc- Mv:9", HD: 1 (6hp), AC: 15, Att: +2, 1d8+1" doesn't require all the text in the MM to tell me what I might need to know in a specific situation. Furthermore, it identifies cosmic "sides" where I don't need to make an exhaustive list to determine what creatures or entities are affected by certain spells or effects- holy word, for example.