I think when non-horsey people attend horse related events it presents a great opportunity to make them feel welcome and, well, educate them.
Some polo clubs have done a great job. Others have failed miserably. The Villages Polo Club in Florida has a booster club with over 1,000 members! The booster club has "lunch and learn" offerings, either hosted or brown bag, where someone in the sport gives a talk or demonstration on different aspects of the game. Horse health, technical, rules, equipement, etc. Booster club members are involved in BBQs and have other events during the season.
Locally, the club I'm affiliated with has a low cost dinner and cash bar after the games on Sundays and players, sponsors and fans are all welcome to encourage camaraderie. Our announcer is great, makes jokes about various players, or tells a funny story about them, and explains it to the audience. If you're the target, you're going to hear about it as you interact with the spectators, which makes them feel like part of the gang!
I think something like this would benefit many equine sports.
I'm more comfortable behind the scenes, but make a real effort to welcome people who seem a bit lost, or try to explain some of what is happening on the field and at the trailers to new observers.
Finally, I think it is really, really important we provide the most welcoming environment we can to spectators. With fewer and fewer people being involved with horses, much less owning them, it may help to have support when our trails are threatened, or barns and ag land zoning is being challenged!