There are several benefits to having large latissimus dorsi muscles, commonly referred to as lats. First, lats help give the appearance of a narrower waist and a V-shaped upper body, which is considered aesthetically pleasing. Second, strong lats assist in performing many common exercises such as pull-ups, chin-ups and rows. Third, well-developed lats can improve your posture by helping to keep your shoulders back and down. Finally, strong lats can help protect your lower back from injury by stabilizing your spine during movements like deadlifts and squats.
So overall, yes it is good to have big lats!