No need to be negative about an idea or product just because it includes electronics/computers. Get past the "firmware update" jargon and consider this:
All complex optical systems, like cameras, need careful alignment to tight tolerances. Sometimes they go out of alignment. Sometimes different components are each within tolerance but together are not optimal. This isn't new. It's happened since the first rangefinder. Every SLR system relies on perfect correlation between the distance to focussing screen via mirror, and the distance to the film plane. Ctein and Mike Johnston have written about the challenges of getting/keeping manual focus SLRs aligned. Add autofocus to the mix, and it's more components and optical paths to keep aligned. As a result, picky photographers for decades have done one of two things --- exchanged lenses and bodies until they got two that worked perfectly together, or sent their cameras AND lenses in to the factory to ensure they all worked perfectly together. Of course manual focus cameras can't be tweaked electronically like this, but they still may need to be tweaked. Instead of adjusting an electronic number +/-, someone has to get in there and start shimming and bending and filing.
Now, thanks to this USB-firmware-coaster-thingy, you have another choice. Keep your camera and lens, and have a play at being your own service centre with this device. Of course it doesn't appeal to everybody -- and if it doesn't appeal to you, don't use it. But I like the idea that I can optimize my gear without sending it away somewhere, or relying on somebody else, or wondering how often I need to send it back. I like to tinker, and if I can plug in my lens to do so, that's great!
Camera makers have recently come to the same conclusion. The top-tier cameras now allow the user to tweak the camera side of autofocus. This is a good tool, one that would have been useful in the autofocus film days too! Sigma have simply closed the loop, and provided the one missing tool for self-calibration -- the lens side. I'm not sure why it's so contentious to be given more control over your tools?
I'll also point out that Sigma have a public-relations reason for providing this tool. I like and shoot Sigma lenses, but often get told by other photographers that they would "never" shoot Sigma, because they "aren't compatible" with their (Nikon/Canon/whatever) cameras, or often need to be sent back to Sigma to make them compatible. This is an over-exaggerated idea, but it has convinced people to avoid Sigma lenses. This "firmware update" tool directly deals with that complaint... it says you won't be stuck with an incompatible lens and you won't have to send it in to the factory if you buy a new camera.