Right, as it turns out it was because Midnight Commander doesn't handle the non-standard extension Info-ZIP uses to store the file attributes.
Whether others have this issue, you don't know. And they don't know, which is not surprising given the rude tone they (or you) reacted to my report. Also, I was actually using a pretty popular app to quickly unpack the archive, so it's more like SS14's problem than MC's. Simply because they are bigger and more wide spread. (Not saying that it wouldn't be nice if they improved their ZIP file handling.)
Anyway, tar.gz is without any doubt the most obvious and safest bet if you are targeting unix systems.
Please consider using tar.gz for the Linux download as ZIP does not store the file permissions and thus the game won't start. The SS14.Launcher should probably be an executable, which itself is a shell script trying to start bin/SS14.Launcher . The shell script can be started without it being marked as an executable but it will fail when it tries to execute bin/SS14.Launcher. I also had to set the execute bit on bin/loader/SS14.Launcher as otherwise the game would throw an exception after trying to connect to a server.