Your reasoning is valid if and only if their gross margins were 8%. But those are their operating margins. Gross profit is from selling products; it simply equals revenue minus product production cost. So if that semiaccurate GF104 BoM analysis was correct, NVIDIA would nearly certainly be selling GF104 at negative gross margins.
The operating profit equals gross profit minus operating expenses (i.e. employee salaries etc.) - which is of course always much lower. It is possible (and quite frequent) to have negative operating margins even though every single one of your products is selling at very high gross margins - simply because you aren't selling enough of them.
One case where it makes sense to say one product has negative operating margins is if you can dissociate its incremental operating cost from everything else fairly accurately. GF106's architecture is quite similar to GF104's and it taped-out afterwards, so it's probably possible to loosely determine the incremental R&D required to develop the chip. So even if the chip sells at a profit (i.e. the more NVIDIA sells of it, the more money they make) it's possible that the product as a whole isn't worth the incremental development cost because they can't recoup the investment over its lifetime.
Of course that is VERY difficult to estimate in reality - how much would GF104/GF108 have filled that gap if GF106 hadn't existed? And from a strategic perspective, that gap in the line-up would have meant higher revenue for AMD - which might mean they'll have more money to invest in long-term R&D, which might make their future architectures more competitive and reduce your future gross margins. So break-even might already be considered a success for a derivative chip like that.
If you confuse gross margins and operating margins, your reasoning will be extremely flawed. And that's before we even consider fun stuff like Gross Margins vs Gross Profit (e.g. improved framebuffer compression would save on DRAM costs, which means for a target BoM you can ask slightly more for your chip and maybe have a higher gross profit - but if it didn't increase in percentage terms as much as your costs, you might have lower gross margins... despite still making more money overall!)
The operating profit equals gross profit minus operating expenses (i.e. employee salaries etc.) - which is of course always much lower. It is possible (and quite frequent) to have negative operating margins even though every single one of your products is selling at very high gross margins - simply because you aren't selling enough of them.
One case where it makes sense to say one product has negative operating margins is if you can dissociate its incremental operating cost from everything else fairly accurately. GF106's architecture is quite similar to GF104's and it taped-out afterwards, so it's probably possible to loosely determine the incremental R&D required to develop the chip. So even if the chip sells at a profit (i.e. the more NVIDIA sells of it, the more money they make) it's possible that the product as a whole isn't worth the incremental development cost because they can't recoup the investment over its lifetime.
Of course that is VERY difficult to estimate in reality - how much would GF104/GF108 have filled that gap if GF106 hadn't existed? And from a strategic perspective, that gap in the line-up would have meant higher revenue for AMD - which might mean they'll have more money to invest in long-term R&D, which might make their future architectures more competitive and reduce your future gross margins. So break-even might already be considered a success for a derivative chip like that.
If you confuse gross margins and operating margins, your reasoning will be extremely flawed. And that's before we even consider fun stuff like Gross Margins vs Gross Profit (e.g. improved framebuffer compression would save on DRAM costs, which means for a target BoM you can ask slightly more for your chip and maybe have a higher gross profit - but if it didn't increase in percentage terms as much as your costs, you might have lower gross margins... despite still making more money overall!)