Seems an awkward way to start a show, and as someone mentioned previously it might be because they don't have an opening video or an opening intro. of any sorts.
Those videos/into's used to build up tension, and then there would be a sudden explosion and a blasting riff rattling and shaking the arena or stadium.
Now you just have plodding Sympathy drum loops...
...but some here seem to enjoy it anyways.
_____________________________________________________________Rip this joint, gonna save your soul, round and round and round we go......