> "Sellers" (riders) don't set their own prices

They kinda do, by not accepting rides under a certain price and forcing a raise, like it has been reported.

> Furthermore, prices are driven down artificially by investors who are willing to take a loss until other "markets" are forced out of business, at which point Uber will presumably raise its prices to actual taxi market rates.

This will never happen. Anyone can start a ride-sharing service with a tiny investment. There's no way bankrupting current companies will give Uber an unassailable market.