Too many things in it.
Good burgers are simple. Bun, patty, maybe cheese, maybe onion, a little salad perhaps. And that's it.
Simple burgers really let the quality of the meat, the cooking, and the seasoning shine through. When that's good, you really don't need anything else.
When a burger is piled to the moon with bacon and guac and relish and six other toppings, you might as well have used the cheapest patty available because you can hardly taste it under all that.