Comment by pjmlp

Besides sibling comment, HPC labs are the kind of customers that get hardware companies to fly in engineers when there is a problem bringing down the compute cluster.

presumably that in HPC you can dump enough money into individual users to make the platform useful in a way that is impossible in a more horizontal market. in HPC it used to be fairly common to get one of only 5 machines with processor architecture that had never existed before, dump a bunch of energy into making it work for you, and then throw it all out in 6 years.