Professional Photoshop users already have existing hardware. This is trying to fill the gap that none (afaik) of the existing hardware offerings support Linux.

Also, if you really care, they say they'll ship a Linux Live CD with the device. So you boot your Windows machine with the live CD, take the readings with the device, save the color profile to a file on USB, reboot to Windows & import the profile. The generated profile itself is cross-platform.

At least that's what they say :)

The only reason it's Linux-only is because Richard is the developer of colord and the Gnome Colour Manager, so obviously writing Linux drivers is what his biggest priority is. It's open-source, so I'm sure he has absolutely no problems with anyone contributing Windows or Mac OS drivers.

Also, I believe the point of the hardware is to bring it down to a price where proper colour management and display calibration are far more accessible to a wider audience. If you're a working photographer or graphics designer, dropping a few hundred dollars on a commercial colourimeter is just a business expense and not a big deal.