When they could be making so much more profit in volume sales.
Like I said before I would rather make a $10/unit profit on 1000 units than a $50 /unit profit and only sell 30 units.
You can not argue with the math (but of course the meatheads will try).
I'm sure Jens would love that, too, if he could find customers in the 1000's. This is a very small market, and economies of scale don't provide a positive benefit. The least expensive Altera dev kit is 150 USD. The fact that Jens can approach that price with his own products at a fraction of the volume is a good thing, and I hope both he and his retailers do profit from it. Jens designs good kit.
EDIT: I can't tell from the photo which FPGA Jens is using. The cheapest FLEX-10K is 32.50 USD per unit on Altera's site.