Correct. Whether or not a card has official GPGPU support is irrelevant for its use in mining, you can use pure Direct3D or OpenGL for mining if you really want

Correct. Whether or not a card has official GPGPU support is irrelevant for its use in mining, you can use pure Direct3D or OpenGL for mining if you really want it. The decision to not support customer GPGPU by AMD only hampers other useful non-mining applications. Ironically, mining is probably the most optimized GPGPU application a regular end-user can run on AMD GPUs. One reason was that GCN was a computing-first GPU, but also that miners have a strong motivation to go through the troubles of overcoming the lack of computing support by AMD. They would write the entire application in OpenCL 1.0 and optimize it to extract the last bit of performance in spite of its difficulties - the hashing kernels used for mining also tends to be much simpler than other applications, so it's feasible to do so. Meanwhile other people who want a decent programming environment would've picked CUDA without looking back.