There are no adult or controversial themes that could alienate any audience I can think of (dice haters?).
Part of the appeal of Eurogames is that they are designed for a more family-oriented market. Settlers of Catan has extremely simple rules that can be explained to a child, or a tipsy uncle. There are no adult or controversial themes that could alienate any audience I can think of (dice haters?). Nobody is eliminated, and the balancing that comes with the social dimension can keep the race interesting until the final turn. Games are of a manageable length, and they don't interfere with more casual conversations between players and non-players.