So why nerf a product with a potentially significantly sized market?
My son, my son, I've said this before. Your logic doesn't work here. No amount of logic works when it comes to GW decisions. It's run by people with papers but fokol passion, actual knowledge, let alone any form of sensibility.
I'll give you a solution, a la GW's own top decision making protocols:
Roll a D6 for your answer:
1: Pull the plug on one army or codex.
2: Make a slightly different scale of models for an upcoming movie franchise
3: We're the best, why try anymore, fans will continue donating their money to us irrespective
4: The eye of the gods is closed, go for a nice cuppa with the lads
5: Khorne is angry, make more khorne sculpts
6: Release a press statement, our fans aren't intelligent so we can say whatever we like, they won't get it.
There ya go. Make choices like a pro.
I have this disease called "Awesome".
You wouldn't understand because you don't have it.