Many development groups treat fixing minor exceptions as a once-in-a-blue-moon event. Sometimes it's just a matter of making exceptions more visible to the developers on a day-to-day basis.
Several years ago I inherited an application that averaged ten customer-discovered problems (with only a few hundred customers) and a system outage each quarter. The logging system was set to email all exceptions to the developers (there were a bunch of low-level exceptions every day.) The outgoing lead developer had an outlook rule that funneled all logging email messages to the junk mail folder; she suggested I do the same. I never did and the annoyance of all those messages in my inbox did wonders for my motivation. After two years, the system virtually never went down and we had almost no customer complaints.
Several years ago I inherited an application that averaged ten customer-discovered problems (with only a few hundred customers) and a system outage each quarter. The logging system was set to email all exceptions to the developers (there were a bunch of low-level exceptions every day.) The outgoing lead developer had an outlook rule that funneled all logging email messages to the junk mail folder; she suggested I do the same. I never did and the annoyance of all those messages in my inbox did wonders for my motivation. After two years, the system virtually never went down and we had almost no customer complaints.