> But what people want at these events is a catchy, flashy demo that wows attendees and that can be tweeted/Facebooked/etc.
And then what? Opened on a mobile phone where the demo doesn't work? Mobile is where people are reading facebook/twitter so if you want to optimize for catchy/flashy for sharing in social media, you should definitely focus on mobile-first.
You're assuming the tweeted link would go to the app itself - it wouldn't. It would go to their roundup of the event. These events are not built around making long-lasting projects.
And then what? Opened on a mobile phone where the demo doesn't work? Mobile is where people are reading facebook/twitter so if you want to optimize for catchy/flashy for sharing in social media, you should definitely focus on mobile-first.