What's the big deal with Terminal lately anyway? What's wrong with good 'ole GUI tools that we can download and install using the all too familiar install wizard? To sum it up in three words, it's speed, power and accessibility.
Open source computing created a slew of new tools and most developers are not about creating OS specific applications to run these little apps. Not to mention, the majority of these developers were/are UNIX devs and they LIVE in the shell.
A shell in computing provides a user interface for access to an operating system's services.
As these tools became more mainstream with developers, especially with devs on Macs, the natural thing was to adopt the use of the Terminal. Sure, there have been some who created GUI apps for some of the more popular tools, but they never really live up to the flexibility and speed that you can get in the Terminal. Not to mention, you are now at the behest of the developer to update their GUI tool as new features are released.