Actually, there are several reasons why taking summer classes would be a good idea. Of course, it'll keep you in town a little longer (depending on if your summer classes are just 6 weeks or the full 12 weeks), but that can be a good thing, academically speaking and just in general.
In General:
-When staying for classes you can also stay for work to make more money. You can also volunteer or intern during these months while you take classes. Or, you might be able to help in a professor's research lab since most student aids tend to leave in the summer.
-More time to explore the area. Perhaps you tend to stay inside during the school year, only going out for a few club meetings or to study in the library, leaving you with little knowledge of activities near you. Or maybe you really wanted to hike a local trail or try a Painting With a Twist class... Well, when you aren't taking your summer class, you'll have plenty of time to actually explore the area and try things you didn't have the time for before!
-More time to focus on one class. Depending on how many summer classes you take, you'll have more time to actually focus on the class. Granted, it'll be slightly more fast paced (especially if it's only 6 weeks long), but you won't have 5 other classes to focus on.
Academically:
-It can give you the chance to take a class that you had interest in but may not be able to fit in your schedule otherwise. Maybe you thought Psychology of Aging Individuals or Professional Writing looked interesting but realized that you are maxed out every semester with just your core classes, leaving no room for these fun ones. Well, now you may have the chance in the summer!-Fulfilling requirements for minors. Sure, you can fit in a class each semester for your ASL or neuroscience minor, but wouldn't it be nicer to have more breathing room during the Fall or Spring semester by taking some of the classes for your minor in the Summer?
-Taking ASHA requirements without as much pressure. Of course, you should talk to your advisor about this, as some graduate schools only want a few classes from community colleges. But, if you're extremely worried about taking Statistics or Physics at your university and heard they are easier at the local community college, this is the best time to take them. Even if you end up taking them in the summer at your university (and not community college) you will still have more time to focus as you won't have other classes to distract you.
-Languages: Learning a language can be difficult when also studying for your major (and minors) during the academic school year. This can especially be the case if you are starting from square one, as most schools have the first two levels (eg. Spanish 1 and 2) count for 5 credits and meet every day. Rather than bogging yourself down in the school year, take them in the summer-- many schools have institutes or even scholarships to learn a language, especially those that are less popular or common. You could also consider taking it at your local community college or studying abroad.
What classes have you taken during the summer? Have you interned or volunteered in the summer?