I totally get why they did, having had to support Mac for an in-house engine. Apple is by far the most painful platform to support out of the big 3 if you're not using turnkey tools, and they don't make up for it with sales outside of iOS. The extra labor is hard to justify already, and then we get to technical deficiencies like MoltenVK, plus social deficiencies like terrible support. It's just a really hard sell all around.