Joao: This is a hard question to answer because the one thing can not exist without the other. The ISS was built to have Astronauts. It can be operated the equipment without Astronauts but there are many things that we can not do from ground. On the other hand, the Astronauts need the equipment to live. So you can’t really have that either. So basically, I would say they are equally important! 🙂
I agree with both – we can run the space station without people no problem, but sometimes you need astronauts on board to fix some things that we can’t operate from the ground if they break. It’s the same everywhere, even with 100% highly advanced, automated systems you need reliability engineering and proactive maintenance. That was my entire previous job – fixing unexpected breakdowns in automatic equipment and programming industrial machines because we had over 800,000 different devices and in extreme environments they’re not going to run 24/7 without human intervention. That’s why we have redundant systems – when one breaks, we switch to the backup, fix the prime, then switch back to the prime or visa versa.