If your job role doesn't require you to spend large amounts of time entering text, and doesn't require vast quantities of information to be simultaneously available on screen, Surface is a perfectly valid option for a business user. If you're spending your time writing powerpoints, doing finance, entering data into a metro app, Surface Pro might be great.
The problem is that Visual Studio is a perfect example of an application that will pretty much always suck on a small screen. It's text heavy (so tablets are a bad input mechanism), it's information heavy (you have a solution explorer and a toolbar and an error dialog and lots of text) and it's going to be window-heavy as well since when you press F5 it's going to open other windows like browsers or Windows Forms.
Or to put it another way, given the fact that most development machines are big, have multiple monitors, fast CPUs and lots of hard disks, it's a bit astonishing that anyone ever thought that a device with a tiny screen, no keyboard by default, a design-focus on power management and a tiny disk to improve portability would ever be a good fit for that demographic of use.
That's not to say that the Surface isn't good for business customers. It's just to say if your business is writing code, it's bad fit for being your main development machine.
I can't tell you the number of devs I know that get by coding on 14" laptops. So it's not quite as bad as you make out. That said, we have a lot of devs here that do really serious development work with those 14" laptops by docking them, where they get full size keyboards, mice, multiple 24" monitors, etc. I can do the same with the Surface Pro. So, why shouldn't I expect to be able to use it this way? DeathByVisualStudio is claiming the HD space would prevent that, but I call BS there as well.