I can only speak for myself, but FWIW, I don't think I'd ever go to a fly-in where I couldn't fly in, at the very least as pax. Unless it was at my home airfield!
There's something special about arriving by air, something intangible, but for me at least, real enough. It wasn't even a fly-in, but I remember when I first went to Duxford for a look round the hangars. Arriving on the correct side of the fence added a magic that would have been absent if I'd driven up the M11 to get there.
The other thing is, discovering the dreadful truth* about this lot means that at least if you've flown there and back the day isn't entirely wasted.
we're not at all like the Addams Family meets the Munsters.