Several key pieces of Edge are open source, such as Chakra Core, which is the JS engine (like Chromium's V8), and more are expected.
The argument IE6 was that the web grew too stagnant with a single dominant web renderer. If we all agree that the Web is a better place with multiple competing web renderers, why wish the death of the Edge renderer when it and Firefox are all that are standing in the way (and barely by latest metrics) of forks from the KHTML/WebKit/Blink family dominating?
This is just ridiculous. The other points may/may not make sense but drop direct-x for vulkan? What? It'd have made more sense to make Direct-X open source than just dump it like it's useless. It's not like windows drivers for GPUs don't support vulkan.
Direct-X has had a history of being the superior graphics API to OGL. Now, VULKAN evens things out a bit but just dumping so much of RnD for nothing doesn't make sense
But to summarize: OpenGL was the standard before D3D was created. D3D has been a step behind OpenGL in features and performance up to about D3Dv7. Then the OpenGL ARB screwed up, with Microsoft among the members (some hypothesize that Microsoft were attempting to sabotage OpenGL).
The argument IE6 was that the web grew too stagnant with a single dominant web renderer. If we all agree that the Web is a better place with multiple competing web renderers, why wish the death of the Edge renderer when it and Firefox are all that are standing in the way (and barely by latest metrics) of forks from the KHTML/WebKit/Blink family dominating?