If you have a lousy database model, you can get around it with triggers. If you need to hide some business logic from everybody else, you can do it with triggers. If you need a mechanism that bypass the consistency in the database, you can do it with triggers. They live a life on their own, seemingly autonomous from everything else and one easily forgets they exist. That is why I hate them. What matters if you do an database export in consistent mode if some active triggers make the data inconsistent during import? Triggers are like secret police, they are threat to the democracy if they take over.
Oh, just a rant.
Note to myself: next time import fails with ORA-1 or ORA-2298, check for evil triggers.