The only possible saving grace is it was running poorly optimised drivers. I still think Vega, on launch, will bench somewhere between a 1080 and a 1080ti.
Pointless releasing it if it's not faster than a 1080. This may be why we haven't seen a release date yet, they may be trying to extract the very last % from driver optimisations for them to beat the 1080 at least. It would be very hard to come back from the public outcry if full fat vega struggles to dominate the mid range 1080.