Back when I was newer to debating theists, I used to try to engage in arguments surrounding theology. I didn't really care much for it, but that's what I found theists wanting to argue about. I thought that I should take the argument on its own merits and went along with it.
What I found was that no matter what I argued, I was wrong. I'd never really studied the bible so maybe I was wrong, I hate it when people take things out of context so I wanted to make sure I was understanding the argument correctly. I took on-board what people were saying so that I wouldn't be wrong. Still I was wrong.
Taking the arguments on interpretations I got from others, it turned out I was still interpreting it incorrectly. Perhaps the people I had learnt about it from initially were also wrong, as well as me looking into it deeper. I wasn't a bible expert after all.
But even then I was still wrong. I just couldn't lay a glove on any theist because I just couldn't interpret it right, even when following what I was being told by theists. I came more and more to the opinion that I was categorically wrong because if I interpreted it right then I wouldn't hold the position I did. Ergo, this type of argument was futile.
The moment when it all hit home was when a theist was trying to argue about Noah's flood. He kept calling God good, and I couldn't understand how he could do that at the same time as condemning murder as evil. His excuse? God gave life so God can take it away, which doesn't actually address the problem and creates a dangerous standard where parents can kill their children.
Self-performed reductio ad absurdum, at that point I realised that I couldn't argue theology, irrationality is inherent in faith so there's little chance of reasoning with someone defending it.
But upon thinking about it more, I don't know why I bothered in the first place. I don't argue about the merits of astrology on the hits and misses of a daily horoscope. I argue that the entire premise is implausible because it relies on an intricate relationship between our relative position to other stars and planets in order to understand the affairs of individuals.
And this is what I should have been doing all along. Arguing the theological implications for God based on the story of Noah's Ark is counting pin-dancing angels. Quite simply there is no evidence for a worldwide flood, despite the many different lines of evidence that should show that such an event happened. Claims about creation are falsified by evolution, claims about a young earth and young universe are falsified by geology and astrophysics / cosmology.
My interpretation of The Courtier's Reply is that it's an Occam's razor for arguments. By arguing biblical interpretations, it's unnecessarily adding extra arguments that don't need to be there. If the underlying assumption that the bible is literal and inerrant truth is false, then what does it matter the implications of an inerrant and literal bible? My contention is over the whether the bible is literal an inerrant, not the implications for original sin.
The Courtier's Reply isn't saying anything new, it just put what we all do (either implicitly or explicitly) into a few witty sentences and gave it a label. The gift of the reply is not the sentiment, it's the presentation. A reductio ad absurdum of those who want to argue over the number of angels, what constitutes dancing, and why on a pin - all without first stopping to work out whether there are such things as angels to begin with.