THE GERMANS LIKE TO PLAY IT SAFE.
We do too.
Unfortunately sometimes life does not go to plan and you need to see a doctor or end up in the hospital. The costs for that can be extremely high and could potentially financially ruin people who only wanted to become healthy again. That is why the German government made it obligatory for everyone living in Germany to have health insurance and therefore it is necessary for international students as well in order to get their German student visa.
But the good thing is: You will enjoy almost unlimited health care and you will not have to pay a bill for treatments in advance if you get public health insurance.