There are many unconventional ways that are utilized here to keep the game unpredictable, and possibly even to combat rogue software, which unfortunately take away from the realism of the game and prevents one from scoring according to their talent level. As unfortunate as it is, this is still the most realistic golf game you will find online, and as Richard alluded to, the more you practice and the more you learn to account for those inconsistencies, and the better you will score.
I am in your camp on this, and agree that these programmed deviations are one of the downsides to this game, but it has been voiced here numerous times, and simply put; it isn't going away, and you have to learn to deal with it.