That could certainly be done, though I didn't convince myself it would work for PyCon. I suspect catering is definitely optional for small events or unstructured things like BarCamps, but for large events it becomes a necessity.
If the conference has 500 or 1000 attendees, the hotel restaurant probably can't handle that many people, so there have to be several restaurants or a mall food court nearby, enough of them so that they don't get overwhelmed by the attendees. That rules out venues that aren't downtown, because suburbs may not have that density of restaurants within walking distance, but such central venues have more expensive room costs.
Another tradeoff: The lunch break would probably have to be 2 hours, because 1 hour is a bit tight for walking time + waiting for service + eating, which means less time for conference programming. Attendees like lots of programming, the more the better; in fact, PyCon attendees asked for breakfast as well as lunch, so it's easier to attend an early-morning event.
And the monetary risk of running an event is large, so like Hollywood film producers, you quickly stop wanting to tinker and try something new; it's safer to stick with a format that's worked in the past.
If the conference has 500 or 1000 attendees, the hotel restaurant probably can't handle that many people, so there have to be several restaurants or a mall food court nearby, enough of them so that they don't get overwhelmed by the attendees. That rules out venues that aren't downtown, because suburbs may not have that density of restaurants within walking distance, but such central venues have more expensive room costs.
Another tradeoff: The lunch break would probably have to be 2 hours, because 1 hour is a bit tight for walking time + waiting for service + eating, which means less time for conference programming. Attendees like lots of programming, the more the better; in fact, PyCon attendees asked for breakfast as well as lunch, so it's easier to attend an early-morning event.
And the monetary risk of running an event is large, so like Hollywood film producers, you quickly stop wanting to tinker and try something new; it's safer to stick with a format that's worked in the past.