I definitely agree with you, but have to add that my (amateur's) take is that this paper has actually contributed a lot. Not only have they shown marked improvements in detection accuracy, but also come up with a trainable model/framework for object detection/classification using only LIDAR point clouds (i.e. without the addition of additional sensor data such as RGB overlays). Not relying on a second (or 3rd, or nth) sensor or hand-crafted features is very impactful to the field.