I know the arrows suit the path direction, but i think it is logical suit the direcion left - right, cause if you look on a line you can not see in wich direction the line was drawn.
We start thinking i have a line in front of me, not designed myself, or a long times ago, i can't not know from what side is original drawed.... So if I visually see a botton-arrow that shows the right side and by clicking comes left side... i think it is strange. If tecnically it is not possible to make this better, ok i understand, if possible mahe changes her my Suggestions: vertically: 1 to 179 degrees right side - 181-359 degrees left side, i suggest 0 degrees right side and 180 degrees left. If a person has always the same result, can remember it, actually it is a random lucky game.
The first question in such a case is what is your path direction. The arrows suit the path direction, not exactly left-to-right. So, if you draw your line right-to-left, the arrow will direct to the left. You can change the path direction using Object > Path > Reverse Path Direction.
To say something more, we need to know your (exact) Illustrator version and OS.