120 is a arbitrary number that doesn't mean anything.
It is okay to drive at a safe speed. This is different for each car and each driver. Some sport cars can do 232km/h safely. Some cars(most cars) cannot even reach that if they wanted too.
The taxi argument is someone who doesn't know anything about cars said if we allow high speeds all taxis would drive 230km/h
Which is impossible.
Then there's also the bad argument that because we are a shíthole country we cannot have nice things. Which is a really bad argument and part of the reason why we are a shíthole country in the first place.
But it is a shot hole country which is exactly why that would never happen. The majority of people don’t have insurance, don’t maintain their cars, so it would never be allowed because of the lowest common denominator reasoning.
The same reason why alcohol is now banned, because the majority of people are not responsible. It’s a social issues mess.