'Business ethics' is a phrase which covers a somewhat shady concept.
Even though every person has a sense of personal ethics (which can wildly differ from anyone else's), in a group of people the sense of ethics can easily dissipate. Psychological experiments and historical examples point out that the majority of people willingly forego their personal sense of ethics due to peer pressure or hierarchical pressure.
However, 'business ethics' is not a completely hollow concept.
The creator of a business can instill a degree of business ethics by creating a clear and transparent business structure. Mission statements, codes of conduct, clear hierarchy and clear channels of communication can contribute significantly to this goal. (Beyond that, it's mostly pray-and-hope.)
On the other hand, 'business ethics' is also a subdivision of 'marketing'. Communicating with potential business partners, target audiences or consumers is easier with a shared sense of ethics.
For short term profit, it is often more efficient if the business as whole sets aside business ethics and assumes psychopathic and sociopathic tendencies. However, for long term profit, embracing clarity and strong business ethics is much more prudent.