Since Linux supports Xilinx ISE, most of the files should be there. Was there anything specific that you thought should be there and wasn't?
Yes, at the moment the firmware update is unavailable in Linux. Linux USB support is not as reliable as Windows USB support (in our experience). The USB device we use does not have very good failure recovery for a bad firmware. Therefore, we decided to leave it out of the Linux version. It is also currently left out of the Mac version, too, but we now use the native Mac USB handling, so we have much more confidence there. And the hardware/driver is much less a moving target as it is on Linux.
You're certainly allowed to have your opinion on what people should do with their hard work. We have chosen not to open the source at this time.
Which distro are you using? We officially support FC5.