Well, it literally is metaphorical cancer, in that it's a case of part (interface design) of a system (software development) going rogue and sabotaging both the

Well, it literally is metaphorical cancer, in that it's a case of part (interface design) of a system (software development) going rogue and sabotaging both the function it's supposed to carry out and system as a whole in a effort to enrich itself, but it's not that great a metaphore.