Yes I agree, bundling expensive cables removes the choice element. BUT you still have a choice. For example, I could buy a Bird and sell the stock 4w 1960s cable for ~$1500 and I bet it'll sell quickly. Same with Odin and Stormbreaker for that matter. However, if I do buy an expensive IEM/cable bundle, chances are I wouldn't need to cable roll to another kilobuck cable, so if you're the type of buyer that wants a kilobuck cable, it's two birds with one stone, so to speak. Whether or not the manufacturers make more or less margin is irrelevant if the cable still carries a similar resale value to the original.But YOU chose the IEM and cable. Also decide if you want to spend that much on a cable, if you feel the cable… back to the whole discussion about cables. That’s the point.
The point is, if you really like what the Bird can do, but don't care for the expensive cable, sell it. Then the Bird cost you as much (or less than) an Erlk or Thummim, and noone seems to complain about those. And if a $6K IEM with a crappy cable does come along, and falls short of the other flagships, it'll be murdered in reviews and the product will fail.
Let's face it, the only reason the Bird hype hasn't subsided in spite of the cost (and "gratuitous" cable) is because it really is THAT good.