FB is their chosen platform
I honestly think events should be advertised in multiple locations, the more the merrier
FB is an interesting thing, my move to Scout initially was because I saw FB as my main competitor, and it was, shortly after when FB took a hard turn to anti gun we saw our number climb again, and each month they get bigger since. But guys supporting FB is gonna bit them.
I predict as soon as the government turns democrat you are gonna see FB turn even harder away from these groups
I cannot ask or force people to use the site, that is their choice