AMD is only doing it because they're at the rock bottom. They had no problems trying to push proprietary standards when they had (or thought to have) the market

AMD is only doing it because they're at the rock bottom. They had no problems trying to push proprietary standards when they had (or thought to have) the market dominance to get away with it – Nvidia's proprietary CUDA was only the response to AMD's (failed) proprietary "Close To Metal" API, there was the failed HydraVision, the TruForm tessellation API, ATi manipulated the Shader Model 2 specification process in their favour to intentionally cripple Nvidia, … and so on. Of course, that all happened more than two years ago, so nobody remembers any more. (See also how they're suddenly public darlings for their cheap CPUs… now that their CPU aren't competitive. AMD had no problems charging $1000 or more for FX CPUs back when they could actually beat Intel.)