"Workstation" computers typically seem designed for graphics/video professionals, or users who run scientific software.
Why have there been so few systems designed for software developers? The only example that really comes to mind is the Developer Edition of Dell's XPS 13 laptop. In this case, "Developer Edition" means that it comes preloaded with Ubuntu and Dell has sorted out any possible driver issues for you. (Dell, are you listening? I'll take one. Thanks.)
Software developers certainly seem like a market worth pursuing. There are over 1.25 million Americans who identify as software engineers or computer programmers. This is a well-paid profession full of people who use their computers in a demanding fashion for at least eight hours a day, nearly every day. Why aren't computer manufacturers falling over themselves to serve this market?
One reason is because it's hard to define exactly what a software developer would want out of computer hardware, other than "fast, has a nice keyboard, and is hopefully portable."
Virtualization might be an answer. Software developers (and QA professionals) love to run multiple operating systems on a single computer, to test their software and take advantage of tools that only work under a particular operating system. Even the most diehard of Linux developers often needs multiple Windows installs around, if she's making web applications and needs to test them on Internet Explorer.
Existing desktop virtualization software like VMWare and Parallels works well, but can be clunky. You can't boot a guest operating system without booting the host, and guest operating systema have limited access to hardware resources like GPU acceleration. Full hypervisors like Xen or VMWare vSphere get around this issue, but are complex to configure and administrate.
I'd love to see a company take Dell's "Developer Edition" approach a step farther and sell a machine with something like Xen preinstalled, so that we could install/migrate/clone/snapshot multiple operating systems as easily as we copy around .txt files today.
Dell, are you listening?