might have made

I once was the guest of the week on a British radio show called Desert Island Discs. You have to choose the eight records you would take with you if marooned on a desert island. Among my choices was 'Mache dich mein Herze rein' from Bach's St Matthew Passion. The interviewer was unable to understand how I could choose religious music without being religious. You might as well say, how can you enjoy Wuthering Heights when you know perfectly well that Cathy and Heathcliff never really existed?
But there is an additional point that I might have made, and which needs to be made whenever religion is given credit for, say, the Sistine Chapel or Raphael's Annunciation. Even great artists have to earn a living, and they will take commissions where they are to be had. I have no reason to doubt that Raphael and Michelangelo were Christians - it was pretty much the only option in their time - but the fact is almost incidental. Its enormous wealth had made the Church the dominant patron of the arts.
? Richard Dawkins, The God Delusion

What does 'might as well' mean?
What does 'might have made' mean?