I think it’s too early to judge Uber’s “contribution to society” when the investors are basically footing the bill for all of Uber’s customers. Let’s see Uber make a profit and it still be less costly/better service to what consumers get now and then we can talk about their contribution to society.
However, the parents point is more general and I think you're talking past it. You can't evaluate Uber's societal contributions based on short term and possibly ephemeral benefits. For example, if ride sharing services suddenly disintegrate once VC funding dries up then they can't be said to have made a meaningful impact. Sustainability is actually crucial.
Far more than Kalanick's behavior, it is the company's practices that are the problem. They willfully broke the law and they also mistreated many people from employees to drivers to rape victims.