Well I started the bet idea because I happen to know someone here who has funds to handle it like I do, and thought it would be fun to see how much faith in their convictions those who advocate the "they all sound the same" side have. And because I think the results (with the video) would make for very interesting discussion. And, of course, because I known I'd win because I've done the same test a bunch of times with my wife just to make sure I could win; one would be an abject fool to go into something like this not knowing for sure when it would be easy to do so.
The bottom line is that if one truly believes 100% that all of properly-functioning DACs sound the same, it should be the easiest thing in the world to accept a p<0.05 bet and that we'd have it set up in a week. But clearly that hasn't been the result. On the contrary, it devolved into all sorts of doubts and fears and caveats micro-requirements and in your case a requirement of almost perfect certainty, which is a completely irrational outcome (excepting, as you well note, the high sum involved and one's personal risk profile), and so forth. I didn't expect that, and find that psychologically fascinating and hugely revealing.