No one was ever misled. Uber facilitated a marketplace that was never intended to include tips. The laws of supply and demand would automatically handle whether drivers chose to make their cars available to the platform. This is the most fair and transparent way for this marketplace to work: all of the revenue transacts on the platform without this side market away from the view of other drivers, other riders, Uber, and the tax authorities.

I like that Uber has stated today that tips are still not expected. However, are they prepared to police the rating system to ensure it doesn't develop into a tool whereby the rider must effectively bribe the system to get future rides?

I guess I, as a rider, could go on the offensive: if a driver posts a sign about tips or otherwise gives me hassle for one, I give a low rating. Still, I'd rather not have to do that...the current system was working.