I can vouch for that point. I spent several weekends at college campuses last summer. Never failed to chuckle when a student pedalled by with his neglected derailure bike squealling like crazy. Saw this very often.

If you're going to park it outside in the rain and snow for multiple years and never clean, adjust, or lube it, I think single speed, fixed gear, or internal geared hubs have the edge.

On the otherhand if you are storing in a garage and are willing to spend time cleaning road grime out of your gears, then derailleurs make sense. You can have a more efficient drive train with wider range of gears with derailures.