And that is precisely the problem. Yes, we chose to do it but I appreciated the work my parents put in to give me the best start in life, to give me a comfortable life and to nurture and guide me. I didn't take it as a God given entitlement. Parents are not their children's servants only there to do their bidding and pick up after them. And remember, being a parent is preparing their child for the world. One day these kids will be someone's partner... And, God help us, parent.
And I'm sorry, your theory on authoritative parenting is incorrect. We've raised five kids, all the exact same way. Some of them are decent, kind, considerate human beings who appreciate the effort put in to raising them. But others are exactly as the OP described.
No one in life should take ANYTHING someone does for them as their entitlement regardless of who it it that is doing it for you.