Why is there no DirectX API for Linux?

Question

Upon considering the driver side implementation for DirectX API on windows systems for modern video cards I was wondering why this implementation is not available on non-windows

Answer 1

Your question is wrong in 2019. DXVK is an implementation of D3D11 and D3D10 implementation for Linux using Vulkan and Wine

Also mesa has native Direct3D 9 implementation but in my knowledge, no one uses it except wine