Uber subsidizes fares ~20% or so currently. Assuming they didn't used to do this, the payout to drivers seems like it would be about the same:
3.75 / 0.8 => 4.6875 (vs $4.90 originally)
The per-minute fees are still quite a bit lower, admittedly:
0.65 / 0.8 => 0.8125 (vs $1.25 originally)
https://pando.com/2014/09/04/uber-continues-to-screw-its-par...
I think it's a valid complaint. He invested in the car based on a business model that changed underneath him. Uber may not be legally liable for that, and may have had valid reasons, but it still sucks. I would want to vent as well.
If the guy had yelled "You are making me accept Uber X fares which is making me make less money" then it would be easy to see where he's coming from if TK pushed back on that - anyways, it's just a technicality but it seems that TK may have actually been correct if all the guy was upset about was the reduction in Uber Black time/distance fees to drivers.
"Lower fares mean that drivers make less per ride. Uber said lower fares will attract more riders, which should increase the number of trips per hour. 'We care deeply about driver earnings,' Macdonald said. 'We actually find that a lot of drivers understand why we do this. They’ve been through price cuts before.'"[1]
So, they try to explain it away by saying the drivers will get more rides, but pretty clear that Uber concedes it's less money per ride.
[1] https://www.bloomberg.com/news/articles/2016-01-09/uber-drop...
Not taking sides (and I'm more of a Lyft guy than an Uber fanboy), but there's really no way to work out whether this whole argument is valid without more information.