I do agree that developers like to find bugs before release. But far too often, it isn't the developer who decides when software is ready for release. Most times those decisions are made by marketing people, or management. So imperfect systems that are not bug-free are released to the public, despite their not being ready for prime time, and the developers then get the blame when the users complain about the systems being buggy. And their complaints go to marketing people or management. But the developer is the one who gets blamed in the end.