I have several problems with such a requirement, these being separated into the theoretical and the practical realms.
My first issue is that community service, unless imposed by a court, is voluntary. That's why it's called "service". If you compel people to do it, how is it different from involuntary servitude? People's best work comes when they want to do something, not when they're forced to do something. What lesson would we be teaching students by requiring them to perform unpaid, involuntary labor as a requirement for graduation?
Our PTSA was really big on the movie Race To Nowhere, in which parents and teachers are encouraged not to require so much of students. They paid for the required teacher screening at a staff meeting a few months ago. The movie encourages teachers not to give homework because the stress causes some students to kill themselves. It was an emotionally-driven movie, as you might imagine, and of course many teachers watched it and were convinced that every moment on the screen was gospel truth. If that's the case, then, why add yet another requirement for students?
My last big picture point is simply, under what authority do we lay claim to students' off-school time and behavior? I've been exceedingly consistent on this point here at RotLC--what students do on their own time is no business of the school's, unless and until it effects events at school. Unlike homework, community service has no direct impact on what happens at school and serves no immediate purpose other than requiring students to give up their off-campus time.
Those are my "ideological" problems with the requirement. Now let's move on to the practical problems regarding implementation of such a requirement.
The most obvious problem would be, what constitutes community service? We have school programs that already have community service as a requirement, would those students be able to "double-dip"? How would we determine which organizations or efforts are "worthy" enough to merit credit for community service? Eagle Scout projects--another "double dipping", or would they meet the requirement? What about students who have jobs in order to help support their families? What about scholar athletes--football, basketball, baseball--aren't they doing enough at/for school yet?
Even if we could legitimately answer the questions above, the next problem is, how would we track this requirement? This is a large paperwork burden for something that doesn't even relate to school.
And what would we do with students who transfer into our school as seniors? How do we impose this requirement on them?
The conclusion that I'm drawn to after posing all these questions is that we'd end up so diluting this requirement as to make it essentially worthless--in which case I'd have to ask why we'd want to impose it in the first place.
What draws people to want to enforce community service on others? Are we somehow trying to promote civic engagement, however we define that? Do we somehow think it will make our students "better people"? On what evidence do we believe this? I ask not only to see if there's a logical, rather than an "I just feeeeeel", answer, but also in response to this article:
The Intercollegiate Studies Institute just released Enlightened Citizenship: How Civic Knowledge Trumps a College Degree in Promoting Active Civic Engagement, which shows that college has zero positive influence in encouraging graduates to become politically engaged — although many universities promote that in mission statements.
If we accept that thesis as true, that just getting an education doesn't promote civic engagement but that "civic knowledge" does, how do we impart "civic knowledge"? The stone has to skip over the pond many times to get from helping at a soup kitchen, for example, to civic knowledge to civic engagement, and many of those skips are genuine leaps of faith.
Notice I haven't even addressed whether it's the school's or the family's place in society to teach civic values, but you know where I come down on this point.
If your school has a community service requirement, please leave a comment explaining what its purpose is and how it's implemented.
Update, 8/27/2013: Another good reason not to do this:
Maryland’s community service requirement — high school students must complete 75 hours to earn a diploma — may reduce their later volunteering, according to a new study. The mandate increased volunteering by 8th graders, but decreased it for 12th graders, concludes Involuntary Volunteering. Instead of creating lifelong service, the graduation requirement may discourage voluntary volunteering.