Never said I wanted it; wouldn't fit my use case right now (though it might in the future). Just trying to articulate what those who want the xMac are looking for, and why they want it; regardless of whether Apple will make it, I don't think their desires are unreasonable.
I don't know the parts and assembly costs and needed margins, so here's my approach: Start with the iMac.
A 27" iMac with the top processor (Core i9-10990) and GPU (Radeon Pro 5700XT w/ 16GB GDDR6) options, 1 TB SSD and base RAM (most will order their own rather than pay Apple's prices) is $3400. To turn this into an xMac, we need to change its existing case into that for a small tower. Let's call that a wash. Then we need to remove the 27" 5k panel and associated circuitry, and add an upgraded processor (Core i9-10990K, which retails for $100 more than the i9-10990) upgraded PS and fans, two PCIe slots (one for a GPU, one for a 2nd storage drive), and two to four more RAM slots.
My guess is that the 5k panel, and its assocated circuitry, costs more than what I just listed. So, at the same profit margin, it's about a $3k machine. The R&D costs for a simple machine like this should be much less than that for, say, a new MBP or iMac. And, countering the per-unit development cost of a potentially lower-volume product is the intangible benefit of strengthening the ecosystem, since a machine like this would probably be popular among developers, engineers, scientists, and independent video pros who can't afford a Mac Pro.
I've never argued Apple would make it. Indeed, the first idea I presented about this, which started this whole discussion, is that Apple likely won't, because it could cannibalize iMac and Mac Pro sales.