Because people have different opinions on morality.  Civic duty is not an objective, quantifiable constant.  It is a matter of personal opinion, with a great deal of variation, and those sorts of things should not be legislated.<p>If you reduce your tax burden from 30% to 20% using legal avoidance loopholes, and you think that one&#x27;s moral obligation to support the community ought to be around 10%, that&#x27;s still another 10% worth of loopholes to find before you&#x27;ll ever feel like picking up litter at the local park.