Most of the business use cases are deterministic in nature. It is really hard to shoe in a probabilistic response in such use cases, as illustrated in this article. It's even harder to convert this probabilistic response to a deterministic response (humans in the loop), at a cost comparable to just maintaining the deterministic system.
There are a few business cases that naturally are probabilistic - ad bidding, stock price prediction, recommendations. The giants have taken over this already.
I am still scratching my head to find a use case for a startup to jump in, use machine learning and solve a growing business use case. Probably there are some healthcare related use cases but I have no idea about that domain.