Again with the AMD bashing... We're talking 4 to 7 years old hardware here! Do you really think they could optimize it any more? Whatever isn't handled through the generic profile will be community-supported, or will require too much juice to matter anyway!
They did wait until Windows 10 and Windows Display Driver Model 2.0 was final before pulling the plug, meaning that you get DX12 support with these old cards from now until Windows 10 dies, and if history is any indication, they'll release the odd bug-fix beta driver in case of serious security trouble or system crash! So, active support is out, but you can still run your games on them.
The biggest let down here is that they pulled the plug before Vulkan was final, but Windows gamers could care less and Linux gamers will get it (if it can be supported on that old silicon) through the open source driver.
On the other hand, it means AMD only has to validate GCN 1.0, 1.1 and 1.2 when they get a driver out - that means better drivers for more recent hardware.