Only problem with a blanket invitation for riders to join a camp out is camp space logistics. I reserve a spot and depending on local regs, the site can contain up to 8 indviduals.
Depending on participation more sites would need to be gotten if available. Sometimes a problem.
One spot we really like in Sequoia NP was rudely taken by a couple ugly old guys and their trailers.
Dang. We coulda gotten all of us, 12, in those two spots and be on flat ground but no, Mr Selfish and their caravan ruined the whole thing. We ended up in a lumpier area.
Caravans park on the paved pads too. Of all the Nerve!
But the place is first come first serve.