That is not how business decisions work.
Keeping the costs down as much as possible is Microsoft and Qualcomm's job, and they aren't stepping up.
They aren't even offering their hardware below cost.
Was the DTK rented below cost? Have proof of that? $500 to rent a screenless 2018 iPad Pro in 2020 (that would have been about what $1000 retail for that config?) seems like a shit deal.
This is indeed exactly how your posts are coming across.
It's obvious that Apple took a loss on the DTK hardware because it was never for sale to the public.
Apple manufactured it, shipped it out to developers, and then issued a credit for the full cost of joining the program when the hardware was returned. They ended up with used hardware that couldn't be sold.
An obvious loss.
Microsoft isn't even bundling a copy of the ARM version of Visual Studio, which would have a marginal cost for them of pretty much zero.
You buy a devkit because you want to support the platform and potentially think it's worth it.