The first generation of HBM was limited to 4Gb and was one quarter the speed of HBM2. It's too early to draw any conclusions on that. You might as well say that because T-model Ford couldn't achieve the 200mph mark promised by todays tech, it can't be achieved.
Except I am an electrical design engineer and have plenty of background in determining what silicon can do and how it works. Everything I have said about HBM has managed to come true, so far.
HBM's design will never provide the 100 times speed the marketing papers tout, except in rare instances, or in fixed benchmarks which are designed to bring out the best possible performance case. If they manage to get 100 times the bandwidth then please feel free to point at this thread and remind me of what I said.
Products are shipping using HBM. The lack of performance gained has been noted and tested very well. Please note, AMD is the one who established the expectations they could not live up to and they knew it going out the door.
Your opinion it is going to get better is just that. I am happy to wait and see what the next revisions show in the real world. I do not expect much, but we will see.