Don Durito
Hero
It seems an odd choice from my perspective.My guess is they looked at 5e's positioning with respect to the OSR crowd and felt it was way too overcrowded a market. The less served market was between 5e and 4e and so that's where they aimed. It's also possible that their addiction to APs leads them to want a system that more strongly supports presenting situations that need to get resolved in a particular order / preferential way and tight mechanics works towards that
What evidence is there that such a market even exists?
The only other thing in that space is 13th Age and it doesn't seem to be a huge seller.