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.
actually it is a random lucky game.
While I do understand your frustration with it, the functioning is not random or (un)lucky in any way. The left arrowhead menu applies an arrowhead to the path's origin, and the right menu applies one to its termination. You may not know which end is which until you apply an arrowhead, but if it comes out wrong, you only need one more click (on the Swap button) to correct it.
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.