My thinking is that Ayre wouldn't supply cables that are inadequate for their components. Is that thinking flawed?
Yes. But its a common enough misconception. So don't feel too bad about it.
Manufacturers build to a price point. For every tiny little part- cap, wire, resistor, every single part- from manufacturers cost to retail is multiplied many times over. Every little thing is scrutinized to get the cost down as much as possible and still deliver competitive performance.
Let's say Ayre decides to include a power cord they are able to build for $50. Their cost. By the time it gets to retail that's a $500 item. Maybe you don't like that, or imagine it will only be $250, or even out of the goodness of their hearts you believe they will let it go for only their $50 cost. That's still added to the retail price.
And everyone runs. The ones who know power cords matter run because they know they can find better. The ones who don't know power cords matter run because they aren't about to pay even $50 for one. Eventually everyone runs. Because, its not just Ayre doing this. You follow your logic and its not just Ayre, everyone is doing it, the market is flooded with these things and the resale value eventually falls to zero. The standard factory power cord is worthless. The baseline has been elevated only slightly, but at the cost of everyone having to pay more.
The same logic by the way applies to every other component part in the box. Aren't the factory feet good enough? The manufacturer thinks so. What about the fuse? Why wouldn't the manufacturer include a shelf and a rack if it sounds better? Why would they even sell this to me, I live in an apartment, they should include a room and acoustic panels. On and on.
Power cords are included as a courtesy, just like patch cords. You aren't meant to actually use them. They are meant to stay wrapped in the plastic bag in the box to be passed along with the owner's manual to the next guy.