My employer, time and time, ad nauseam at times, talks about customer engagement.
For better or worse, during irregular operations, delays, or even normal ops, they want you interfacing with the customer in the terminal, onboard, yadda yadda yadda. There's a million schools of thought about this and a number of opinions, but I think part of the volunteer spirit means that you probably won't be 'above' stopping in the terminal to ask a person who looks lost if you could provide assistance. We get a good letter about a "Grunt does good" and a good letter about "Grunt does bad or underachieved" every week and they're serious.
I think that's why they ask the question and want to know if you're a volunteer at heart. If you check it, you'd better be ready to talk about it.
If it's nonsensical, a waste of your time, etc, there are many other airlines that you can apply for that may not find it important in a new job candidate. *shrug*
If you want to be a Submarine Commander, well, do what you think you have to do to get command of your own vessel. But I think they're trying to elucidate that flying a jet is only part of what they expect out of a job applicant.
Anyone can fly a jet. But can you fly a jet, handle a abnormal passenger situation smoothly and are you going to sigh loudly when someone asks you for help in the terminal? Or are you expecting to sit in the cockpit with the door closed and your ipad out during a two hour long delay?
Speaking of that, one of my captains was on a flight on another airline that was delayed with passengers boarded. The two pilots had the door open, laptop out, watching a movie and said nothing for two hours. I can guarantee you that would be a carpet dance.