Well, they managed to murder someone - I'm not sure the fact that it was or wasn't closely observed makes such a difference.
There can be a fair argument as at what stage would it be necessary to remove the driver, but I think the main thrust of the issue is that to the clients, it is promoted as a taxi service and to the drivers, it is promoted as a dating service.
EDIT: This is literally what happened:
"As Huang Jieli—the woman who had served as Hitch’s general manager until she was demoted last week—said in an interview in 2015: “Like a coffee shop, or a bar, a private car can become a half-open, half-private social space. It’s a very sexy application scenario.” And in another interview (link in Chinese) in 2017, she said “the biggest motivation for our drivers is to share a trip with a passenger.”"
I agree that the problem isn't "the company should or could have done something to detect and eject the murderer-to-be", there's always going to be a few individuals with extreme behaviour, and in any given instance it might be tricky to prevent that, even if companies or organisations are aware of the risks and acting in good faith to minimise them.
I agree with your characterisation of the problem:
> to the clients, it is promoted as a taxi service and to the drivers, it is promoted as a dating service.
The company is misrepresenting what the nature of the interactions between drivers and clients in its marketplace. This misrepresentation predictably increases the risk to women who use the service --- it should not be surprising that a service that allows drivers to see photos and share tags of clients before they agree to take rides structurally and predictably offers more opportunities for abuse. This is frankly pretty foul. I hope the company continues to get hammered for it.
For example, suppose didi was an online dating service, and clearly and unambiguously advertised itself as a dating service to all parties involved. How many women would choose to go on a first date with someone they'd never met before by getting a ride in their car? You're obviously going to be far, far more at risk and unable to get away if the person turns out to be abusive than if you meet in a more public location.
> The service had a feature on the app that let drivers tag passengers with phrases like “long legs” and “hot as hell.” All Hitch drivers were able to read the tags, which have since been removed from the app, and they were also able to specify a preference for female or male passengers,
