I trained months in Thailand, and the instructors (pros or ex-pros) were always sparring ultra light as they didn't want to get injured before their matches, and also because it's a better way to improve. In the West, some (rare) guys tend to have a bigger ego and may actually get some pride to harm beginners in sparring which is a bit ridiculous. A healthy gym will typically discourage such behaviors.

Coming back to my initial point, I feel it's easier to spar lightly in boxing than in judo.