The response to The Enemy was disappointing. It’s wrong, said many, to encourage your community to have an enemy.
Saul Alinsky just snorted in his grave.
Two points here. First, your community will probably already have an enemy, even if you don't know it. If your community stands for something, then something has to stand against it (otherwise it would just be accepted reality and your community wouldn't be needed).
Second, and most importantly, we're community professionals. We take a group of people and build a strong sense of community amongst them. A good community tactic grows and strengthens the sense of community between members. A bad community tactics does neither (or weakens it).
Knowing your enemy is a good community tactic. It increases the strength of community amongst individuals. By knowing what they oppose, they feel a stronger sense of connection with one another.
Having an enemy will galvanize people into participating more frequently. They are more likely to take actions to help each other and volunteer to help out. Having an enemy encourages people to join and be part of something. More growth, greater participation, clear actions, this reads like the christmas wishlist for community professionals.
Stick to 'being a good host' if you like, but you're missing out on a broad spectrum of proven techniques for building and strengthening your community.