Why? Because people can do something more meaningful with their lives if they are are currently doing something that can replaced by a robot. (There will be other jobs that are created to fill the replaced jobs). Arguing that we should not innovate and progress as a society because it will take away jobs is like arguing that we shouldn't have toilets because it will create less jobs for sanitation workers.

I don't think your notion of transferring wealth from workers to the owners of capital holds much weight in the context of a sharing economy either. It seems to me that a sharing economy is simply a more decentralized way of doing business, in which individuals are leasing their property or providing their services more directly to consumers than before. A centralized economy still provides wealth from workers to the owners of capital (rental car companies, hotels, taxi medallions, etc), perhaps more so than a sharing economy does.