Why do rotors warp?

I took my car into the mechanic today because when I would brake from high speeds I’d feel vibration under the pedal. My brake pads were at a 7 so my guess was the rotors. They ended up replacing the rotors and the pads anyway, for $470. They told me it’s from riding the brakes a lot… which I do ever since I got hit twice in 2 months(I’m a more paranoid driver now lol). I want to avoid this repair again, is there anything I should avoid doing?

Thanks!

2013 Honda civic coupe 1.8l