Well, take your float tube (it's a boat, isn't it) and launch it there (then tether it someplace and go wade) :-)
On the serious side, if the DNR leases a sportsman access and it is taken over by swimmers and partiers I can see it being a problem. It might prevent someone from renewing a lease or such.
I don't know about this site in particular, but any public access site has the potential for getting out of hand. Unfortunately it's the world we live in. It would be interesting to know why they closed it down.
Carl