With sparring featuring the real-time drama of victory and defeat, drilling is boring as hell by comparison. This is big reason why I feel a practitioner should be decently proficient in drilling before making the leap to combat, as they’ll likely never want to drill when faced with a choice to either isolate or bump bellies.
A side benefit to the above is good drilling requires cooperation and attentiveness and goes a long way to help screen for potential a$$holes.
Finally, to the J-O-B analogy, told a friend yesterday to think of drilling as a day job you love. It’s a job and not always going to be fun, but at least your doing something you love, and it pays you for time invested.