Bug-compatible

People who use any piece of software (or, perhaps, anything) long enough will become accustomed to its fault, regarding those misbehaviors as quirks of the system. Some of the quirks are interesting enough to be regarded as features.

Then, when it comes time for an upgrade, users will howl like three-year-olds fixes something that they've already adapted to. This story is a fine example of what we at a former company used to call a bug-compatible release.