My friends from europe didn't use malaria pills in india when we went on exchange. Why did I have to?

Diff't VIEWS on RISK. Antimalarial rx in india: depends on where you're going and how long you'll be there. It also depends on your (& your doctor's) view on risk: some experts (our euro colleagues) recommend "standby treatment" instead of "prophylaxis" for travel to india. In us we're more likely to recommend prophylaxis. See a travel medicine expert. Find one at www.Istm.Org (international society of travel medicine.
Because you're smart. You don't have to take anything, but if you have ever had or seen patients with malaria you would do everything possible to prevent your getting it. In addition to being incredibly ill with it, it can be fatal, and there are areas of the world in which the plasmodium species are resistant to most available drugs.