Unions
No, seriously. I think it's always really easy to overlook the human factors and why they quite possibly would not change even in a technologically advanced future. When the station was constructed, the unions all came together to set working conditions for their members and one of the required conditions was that there be a certain number of human traffic controllers on duty at all times. (Possibly this was even at the insistence of the Trade Union, which runs the ships.) It might have nothing to do with the safety of the computers that could run the show. "We want guaranteed jobs in the traffic control sector or we're not serving your station." So, they bent to the union and now there's some traffic controllers.
Government Quotas
Similarly, it could be a government mandate. With automation and computers everywhere, the government stepped in and started setting laws on how humans need to be hired at certain ratios. Or perhaps the station was built partially or entirely with government money so the government simply has stipulated that "this station needs to employ this many people" and "well, we could set up some traffic controller positions" was how the people in charge of the station met the quotas. 824
Might be the computers still do most of the work, but the station controllers have their own quotas of manual landings to perform so they stay in shape "in case of emergency".
The Station is Poorly Run
Actually, the computers would definitely do a superior job. Maybe it even was automated in the beginning. But over time the system began to degrade. Sensors would go out and not get replaced. The whole station is running on bubble gum welds and duct tape so throwing a body at a terminal and saying "Go help these guys land" was easier than trying to refurbish the sensors and networks required to let the computer do it.
I'm kind of a fan of very mundane explanations in sophisticated sci-fi stories, lol. I do think it helps keep the story grounded. "Why isn't this automated? Is there something wrong with the tech? Are the computers too smart? Are they not smart enough? Are there hackers? Aliens? Alien hackers!?" "Nope. Governmental regulation." 197