What workload do you have that is easy to run across two separate hosts? And how easy is it for you to maintain the workflow? Sounds like a pain in the butt unless you’re using them in a headless fashion.

Unless there is one single never-ending processing task... forever... I see your point. Generally, everyone else has a never-ending series of processing tasks that obviously can be shared between as many processors as are available. Otherwise, we'd only ever need one single computer and one single person operating it.