Both evil and rude, but with the additional connotation that the rudeness was due to malice rather than incompetence. Thus, for example: Microsoft's Windows NT is evil because it's a competent implementation of a bad design; it's rude because it's gratuitously incompatible with Unix in places where compatibility would have been as easy and effective to do; but it's evil and rude because the incompatibilities are apparently there not to fix design bugs in Unix but rather to lock hapless customers and developers into the Microsoft way. Hackish evil and rude is close to the mainstream sense of "evil".

[Jargon File]