In a society built around business competition, interference with prospective business relations has never been thought to be wrong in and of itself. Indeed, it is to be approved. Some people have tried out the idea of malice. But the common law is very uncomfortable with malevolent motive being that which makes something tortious. The common law strives to find objective criteria for tortious conduct.
Subjective factors are just too hard to deal with.
If a person does something legal with a mean spirit, the person has not thereby violated the law. No law says, Act only in a positive manner on pain of paying damages. It begs the question to say that there ought to be a tort of injuring someone deliberately, without justification. It is very little help to articulate a list of potential liability factors and simply invite judges and juries to savor the stew. This smacks of subjectivity, relativism, and unreason.