Again: been there, done that. Good for you (and others, even if they don't know) that it worked, but in my case it didn't. Part of the reason is that FB is also the place where events get promoted. The integration is so tight that any other solution is an inconvenience to the normies, ie. the 99%. You have your events, your communication tools and your audience, all in one place, it's effective. FB is eating the world really... convenience for the masses.

Luckily, I have other hobbies that are less prone to this, mostly because they don't involve much event promotion if any at all and don't need any audience to exist. Example: my local shooting range uses a mailing list for communication and you can always hang with fellows at the club-house.