For context, I'm working in cloud infrastructure. Due to customer demand (esp. from customers with large in-memory DBs), our newest set of ultra-large VM flavors goes up to 3 and 6 TiB RAM. I'm not directly involved with compute, but from what I gather, it's an interesting challenge esp. on the operations side. You can migrate a 4 GiB VM in a pinch if the hypervisor is looking bad. Migrating a 6 TiB VM, however, takes a substantial amount of time (22 minutes if you have a 40 Gbps link and can saturate it, which you usually can't).
My complaint is the testing methodology. Server vs server is a different problem/requirements. They compared a workstation and then built a workstation with memory requirements that were more common to a server class machine. I suspect a cheaper 'non-server' CPU, with a memory footprint that was more typical for a workstation load, a cheaper option would have held up. One of the likely reasons they gimped the threadripper was to ensure it did not compete with the epic product line.
As for the questions: no, no, no, no, no, no, no, and no. :)
Are you arguing that no one needs >256G of memory? Or are you arguing that no one needs ECC memory? Or are you arguing that server chips and motherboards shouldn't exist? Or is your complaint that Apple sells a workstation? Or maybe you think workstations should be illegal?
Should car makers only sell cars that you, personally, would like to buy? Should all manufacturers only sell things that you personally find useful? And if you don't find this computer useful how valuable is it for 100 people to chime in to say that? (IMHO opinion polls are better suited to that level of commentary.)
> I doubt the workload they put on things used that much memory
All anecdata to the contrary some workloads do in fact benefit from obscene amounts of memory. And if you've ever looked into it supporting >1TB of memory requires expensive dense memory modules because there are only so many memory busses on the chip and only so many sockets you can put on a bus.