With the ASUS Nexus 7, rooting is almost unnecessary. Since it is possible to easily unlock the bootloader and install a custom recovery, many people skip the tedious steps involved in rooting the stock firmware, and simply skip straight to installing ROMs. Of those who do decide to root their devices, though, most use Windows, meaning that the best (and sometimes only) automatic rooting solutions are only available on Windows.
Usually, Linux users seem to prefer rooting manually to the automatic options anyway, but sometimes an automatic utility can be quite useful. Recently updated to version 1.6, the Nexus 7 Simple Root Tool found on XDA is the best Linux utility I have found so far, and can unlock the Nexus 7’s bootloader, install a custom recovery such as ClockworkMod or TWRP automatically, and add root access and install SuperSU automatically. The utility is distributed in a simple Tarball file, which contains a script to be run by the user and all supporting files.
In the past, I’ve actually had automatic utilities work when manual rooting didn’t (and vice versa), but the one thing that is always consistent is that it is difficult to find good automatic utilities that work on Linux. After testing the automatic utility on a friend’s unrooted Android 4.2 Nexus 7, I can definitely recommend the N7Root Simple Root Tool to those Linux, and potentially OSX, users who need to root the Nexus 7’s stock software.
Whatever the reason, although it is nice to be able to root a device manually, I actually prefer to use automatic utilities, provided that they work properly. Usually, when I find an automatic utility, however, it doesn’t work on Linux, which is why it is quite nice to find one that does.