IMO it's not about what metric is used, but how it is used. The current approach, completely avoiding any karma like mechanism, solves the farming issue, but IMO does not cater to the needs of every user.
For example, I have ADHD and if accumulating karma gives me much needed motivation and feel good chemicals, I am going to take them.
At the same time, holding a user to a higher regard because of their karma is stupid, it's better to build real connections with usernames you recognise through continuous communication.
Personally, karma was an easily digestable piece of information about how my outreach into the social media is performing. Accumulating karma helps me feel connected with the community, feel accepted.
The best feeling of my lie? Getting fired after returning from vacations.