Maybe that's the real problem - people think they are paying for the
wireless network as part of the conference fee, when the reality (as I
understand it) is that a substantial part of the cost of the wireless
network comes from sponsors, donors, and/or volunteers.
The network (i.e., internet connectivity, wired infrastructure, and
wireless) is the responsibility of the local host or in the case of the
no-host meetings (like Minneapolis) the IETF secretariat. So I think at
least in the case of the no-host meetings we are paying for the network
(wired and wireless). My understanding is that even with lots of donations
of services, the network is an expensive undertaking. Also, from our
experience hosting the Atlanta meeting I suspect that not having a terminal
room and only having wireless access probably saves money.