I think it's pretty obviously self-deprecating, and about himself in relation to his new album. Especially the part about making holes in a quarry. A quarry is already a big hole. So he's down underground where he can't be seen, doing what's already been done. It's pointless. He's got nothing new to contribute, nothing to say, and no one cares to see his work anyway. He never has had anything original or worthwhile to say, he says, like one of those punk kids breaking bottles in the park in the name of anarchy or some other half-baked, trendy new philosophy. So when should he finally stop this meaningless thunder and "gracefully retreat?"
I think it's pretty obviously self-deprecating, and about himself in relation to his new album. Especially the part about making holes in a quarry. A quarry is already a big hole. So he's down underground where he can't be seen, doing what's already been done. It's pointless. He's got nothing new to contribute, nothing to say, and no one cares to see his work anyway. He never has had anything original or worthwhile to say, he says, like one of those punk kids breaking bottles in the park in the name of anarchy or some other half-baked, trendy new philosophy. So when should he finally stop this meaningless thunder and "gracefully retreat?"
That's what I got out of it, anyway.