From my own skimming of the paper, the discussion of 'why?' boils down roughly to 'exploits are sometimes used for bad things'.
Do you believe your approach will actually improve the security of any systems, or will it just allow lazy vendors to hide their shallow bugs - leaving them to the most motivated (e.g. nation-state) adversaries?
If you or anyone else is interested, the strongest approaches when I last looked at everything tried to create full memory safety or do properties like CFI with strong assurance. Softbound+CETS, SafeCODE, and Data-Flow Integrity focused on memory safety with less performance hit. Code-Pointer Integrity with segments had low overhead. Some people were talking about S+C combined with DFI but overhead was crazy. I encourage folks to look at that kind of work, look at whatever [fast] mechanisms are in modern hardware, look at any software improvements in literature, and try to reduce the overhead of techniques like that (esp in combination).
Similar to you, I proposed we use techniques like Softbound+CETS on proprietary, closed applications to increase their security at a performance loss that can be made up for with cheap hardware. And then sell them on that saying security personnel cost way more than a few more rack servers.