Remember how time consuming it was to write raw CSS? Remember repeating yourself countless times writing color codes and selectors? This is why having a little bit of SASS is only logical.
As you get more comfortable with the features of SASS you'll realize that you have a serious tool on your hands that makes life as a front-end developer almost pleasant. As your projects get larger and larger you'll find that offloading the heavy lifting to SASS just makes sense. Further, many of the most popular front-end frameworks you use are built and configured with SASS. At the very least many provide SASS configuration and customization.
SASS and CSS preprocessing is basically a requirement for front-end developers in this day and age so be glad that you've take the time to tuck it into your toolbelt.