My understanding is that just by calling it an ebike, it suggests it fits the usual legal requirements and is generally misleading.
I kinda get what you are saying, but personally I don't think it's misleading to call them 'ebikes'.
I don't see the situation any different to the 1000's of retailers selling 60mph+ escooters, but those retailers aren't getting hit by the DVSA.
I am sure the ebike case must have something more to it, but I don't know what (yet).