Another article by Mary Terresa Bitti points out that "Volunteering is something you do because you want to, not because you have to. What message are we sending teens if we are equating mandatory community service with volunteering? Volunteer or risk not graduating?" Forcing teenagers to volunteer with hthe risk of not graduating is more of a threat than an incentive. Most people are resentful of the idea of labor without pay.
I'm siding with no service program. Mandatory service would deter teens from wanting to help the community more than anything, and the work without pay when being forced to do something they didn't want only makes the resentment worse. It's technically not even volunteering, it's just labor to them. There would be no built character or self discorvery if it were forced. The only thing that would be found is burning resentment and calluses on hands.