Hi!
I managed to get the Connect IQ SDK 2.1.4 working on Linux (using Wine). If you are interested, please see my installation instructions at
http://johann-glaser.blogspot.co.at/2016/10/garmin-connect-iq-on-linux.html
I didn't yet try the Eclipse plug-in, but I'll add more on that.
However, just because the SDK works in Linux, I still ask Garmin for a native version. The major effort will be to get the simulator and its remote control "shell" working on Linux. However, just take GTK or Qt, and the program will work on all three, Linux, Windows, and Mac OS. Apart from that, only minor tweaks for the scripts are necessary.
Thanks
Hansi