There are two reasons that you might prefer to clean your own gutters. The first is the fact that doing the job yourself saves money.
The second reason you might prefer to clean your own gutters is something less tangible. Taking care of your home and completing a large and important chore like this will give you a sense of accomplishment that will not be there if you pay someone else to do the work.
There are also two reasons you should hire someone to do this chore rather than doing it yourself.
First, gutter care can be a dangerous proposition. There are safety concerns with getting up on a ladder as well as possible health concerns over coming in contact with certain molds and bacteria. If you are accident prone or have serious mold allergies, then hiring a professional is probably a good idea.
Second, there are certain added benefits you get from a service like gutter maintenance and upkeep.