How does piercing effect the community?

I will answer this from a professional body piercers stand point and we will consider "piercing" as a service provided by licensed and inspected facilities staffed by knowledgeable trained individuals.

Professional body piercing allows individuals who desire body piercings to receive said in a safe and professional manner with interest on public safety and hygiene.
Professionally provided services support wholesalers, vendors and other subsidiary businesses by conducting business for support services, materials, advertising, leasing shop space, insurance and renovation costs and supplies from building supply stores as well as services of trained tradesman , electricians, plumbers, heating contractors etc.

In the provision of service we also require the assistance of government offices for licensing and building permits, inspections and other municipal infrastructure support.
We cut down on the loading of the health care system by providing an professional service where one service like ours may not be available, thus preventing people from injuring them selves to attain a piercing and requiring medical assistance due to stupidity or lack of knowledge.

We educate the public in the correct methods used to receive a piercing as well as the methods used to heal and look after a piercing which they wouldn't normally have access too if our business was not available.

We pay taxes not just municipal but federal / state taxes for the services we provide and thus pay back into the economy, just like an auto manufacturer or home builder, Lawyer or Doctor would pay back to the system that supports them.

We are a legitimate business in a legitimate industry we pay for the rights to provide our services to the public who look for our services and in doing so they pay into the economy themselves by receiving our services.