Kali Linux is so different that the fine folks over at Offensive Security thought that to solve the ‘inherent problems’ of BackTrack the authors needed a complete re-write. The main issue with BackTrack v1-v5 was that it was a headache for dependencies. Here was the problem: too many pentesting tools embedded within BackTrack all struggled to co-exist within the dependencies. Many pentesting and security tools where not regularly updated by their creators so the result was that trying to update the entire OS often caused conflicts and tools would simply stop working, crash or even cause other tools to crash. A good example of this is Ettercap which was not updated for a long time.
The solution was to rebuild the distro bottom-up by making Kali Debian based. Before with BackTrack there was a /pentest/ folder, whereas now it is all updated and managed by Debian packages.
Kali Linux has 300 tools which automatically work within the Kali ecosphere. Kali also has been created with the clean “File system Hierarchy Standard” and offers vast plug and play wireless support, with the only exception appearing to be broadcom.