1. It looks beautiful, displaying a wide palate of colors over the course of a year.
2. Because it looks so nice and because there is a lot of it, your eye, clubface and ball are drawn to it.
3. As you walk to your ball and your feet meet the very dense problem, there is the emotional torment of knowing that you won't find your ball. In fact, the white ball really pops against the dark colors of heather, and one can almost always move forward.
4. The ball can be sitting way down but often is perched up nicely "on top of" a clump.
5. In which case you might be tempted to try a six or seven iron.
6. Ha ha you always need to wedge it out. I have heard rumors that wedges with bounce are no good and that you actually need to slice through the flora with a pitching wedge, and try for between five and sixty yards depending on the "lie". This difference in distance can be quite meaningful regarding strokes gained depending on how close you are to the hole.
Is there a better hazard? The combination of aesthetics, findability, sheer temptation, and strategy seems pretty good to me.