Yes, from a performance standpoint there's no reason to go after this type of system. No one is arguing this is a good system for production work.

The application of this is a teaching model. It's a lot easier to demonstrate parallelism gains on this type of platform. Scaling beyond a single ARM core is going to give you immediate performance benefits. Scaling further out to the entire cluster will continue to show returns.

With a single desktop, once you go beyond ~4 cores the gains will drop off too quickly. You just won't be able to see gains out to 64 threads on a single CPU, where on this you should.

It also doesn't hurt to have a quirky architecture to get students excited by. And yes, you could also spend some time discussing the architectural trade-offs and why this is not a cost-effective system for production use.