Not surprising. People actually in the market for STEM play things will get their kids telescopes, microscopes, chemistry kits, soldering irons, computers, hobby robotics/electronics parts, ...
The market for people who want STEM play things, don't know what to buy, and can't tell crap from gold, has to be incredibly small
Actually the second group you describe is the huge majority: Many parents have heard about STEM and programming and want their children to be exposed. However, being non-techies they don't know where to start.
Also, a large number of Christmas toys are bought by grandparents,where the above problem is even more prevalent.
Sorry, I meant to say "and CAN tell crap from gold".
I was saying that there may be a huge market for STEM toys, but the savvy consumers aren't included in that market (already well-served by the normal STEM stuff) and unsavvy customers will just by the stupid crap that says "STEM" on the label.
The market for people who want STEM play things, don't know what to buy, and can't tell crap from gold, has to be incredibly small