Yes, some exercise routines require well over 2000 calories a day, but that's still pedantically missing the point of my comment.

If somebody is confused about why they need to burn 3000 calories a day to keep from gaining weight, they're eating too much.

Serious cardio will burn a LOT of calories. If a person who is NOT doing serious cardio needs to exercise to a 3000 cal deficit every day to maintain weight, they should lower their caloric intake.