I don't see any good to close it to the public, for ANYONE.
We in this hobby need exposure- I have been to only one York (October 2018), and I thought that one was terrific. One of the best parts was seeing the public- not thousands or anything, but a lot of families, grandfathers w/ teen and younger grandchildren, all people who we would love to have in the hobby.
One day of only Members- fine, but otherwise let's promote the hobby!!