To make themselves look better ?
For the same reason Mayweather fought McGregor.
Yeah, but that also means that Intel is creating some confusion among potential buyers. Unless Intel is just going to spam the market with Cascade Lake-AP for awhile as their premier Xeon product for pretty much everything.
The current HPC paradigm is highly-parallel, efficient CPUs hosting compute cards, whether they be GPUs (Summit) or Xeon Phi cards (Tianhe). Cascade Lake-AP sort of takes the "you can have your cake and eat it too" approach further than Phi ever did, by being fully-capable x86 "general purpose" CPUs that just happen to have a little grunt in the HPC arena as well.
Still, I don't see Cascade Lake-AP stacking up very well against anything from Nvidia.
I also thought about this. I mean it performs the best in very parallel BW heavy tasks, that take advantage from AVX-512. Many of such tasks run even better on GPUs, which offer more BW and parallelism.
The main problem with gpus is rewriting your codebase in CUDA, or the fact that the problem might not be easily be splittable to chunks thst fit into the GPU memory. But these look like niches of a niche market
Most of the HPC market has embraced CUDA and/or OpenCL. I have to admit, it would be stupidly easy to code for Cascade Lake-AP, though. Easier than Phi ever was.