Yes, there were a lot of "rogue" DHCP servers at LCA, although a better term might be miss-configured because I am almost certain it wasn't deliberate. But the story neglects to mention the reason. Attendees were invited to set up wireless access points because the accommodation didn't provide wireless. There were I guess 20 or 30 units, and I be surprised if every one of those units didn't have at least 1 AP set up by a community minded resident. It is inevitable that some of those will have forgotten to turn DHCP off, or perhaps plugged the internet connection into the switch rather than the upstream port on the router.
This is avoidable. LCA owns some 50 or so access points, which have been deployed in the past to supply wireless to the accommodation. Doing so means the attendees don't bother unpacking their access points, and the rogue DHCP problem goes away. However, deploying those access points takes a substantial amount of time and organisation. LCA is run by volunteers. So they have a tradeoff - they can put in a substantial amount of work and the problem largely goes away, or deal with the problem during the conference as it arises. As LCA attendees are a pretty sophisticated bunch networking wise, either way works well enough.
The one thing that doesn't make any sense is blaming the attendees, which is the way this story tries to slant it. That is like leaving the nappy off the baby and then blaming it for the piss on the carpet. The consequences of not supplying wireless are entirely predictable. Reasonable adults either supply wireless, or accept the consequences and don't whinge about it.
A more interesting topic of discussion is the collapse of the network in the accommodation on Friday night. In hindsight the cause is obvious. For the second LCA in a row they got all most of the conference video's up before the conference closed. Come Friday night many attendees decided to download huge quantities of them, the usual reason given being "so I have something to watch on the way home". It was a really good idea actually - LCA this year had 4 streams, and inevitably people ended up missing what in hindsight were "must see" talks. The problem was the link between the residences and LCA simply could not cope with the traffic.
Again, that could have been solved. Indeed it was solved at LCA 2011 using DNS tricks. In that year a copy of the videos was put on a server in the residences, and FQDN for the video server resolved to that server for the residences only. Or perhaps enabling torrents for the videos would have worked well enough. As it was, internet connectivity was almost non-existent Friday night, and that caused howls of anguish - far more anguish than the rogue DHCP servers.