Yeah, I think the decision was made that way because they wanted to try to catch up to CUDA but probably didn't really have good tie in with the driver team to put ROCm there. IIRC for a while you used to also have to install a custom driver to use ROCm, although at least that hasn't been necessary for some time.
With ROCm on 5000 series they promised status updates several times which never came and the eventual unofficial support came after 6000 series was out. Then with the Rx580 support, they claimed that while it was unsupported it should still work and several of their developers claimed to be looking into the matter. I recall other similar incidents regarding their other smaller projects under GPUOpen.
So overall it always seemed like they weren't really communicating properly internally, thus all of their projects seem somewhat disconnected from each other, leading to odd decisions like this one.
This is one of the reasons I don’t bet on AMD for GPU outside of gaming. All the other GPU vendors (NVIDIA , Intel, Apple, Qualcomm etc ) are investing strategically on making sure popular software is hardware accelerated by their products. NVIDIA is clearly in the lead here, due to the excellent choices for CUDA, but AMD is the only vendor who seems to not be pushing forward here because their HIP and ROCm strategy seems to be flawed.
On the other hand, I don't think any other vendors aim for compatibility with CUDA. Intel is laser focused on oneAPI which is just SYCL iirc. Sure, SYCL is cool and all, but you cannot trivially translate most CUDA programs to SYCL like you can with HIP.
With ROCm on 5000 series they promised status updates several times which never came and the eventual unofficial support came after 6000 series was out. Then with the Rx580 support, they claimed that while it was unsupported it should still work and several of their developers claimed to be looking into the matter. I recall other similar incidents regarding their other smaller projects under GPUOpen.
So overall it always seemed like they weren't really communicating properly internally, thus all of their projects seem somewhat disconnected from each other, leading to odd decisions like this one.