Haven't watched the vid, but here are my thoughts.
(1) People will spend $ on what makes them happy, no matter the economy.
(2) We provide forms of entertainment that build community and prevent the kind of sense of boredom and isolation that, in the extreme, render more likely folks feeling alone & depressed & turning to inappropriate forms of entertainment (or much worse).
(3) We do have the charity auction. Though personally, I would've picked a grassroots one.
(4) We obviously promote a lot of business for a lot of folks.
However
Yes, absolutely, I believe that the amount of $ that any individual puts into con could be drastically reduced, with some of that better spent on --not necessarily charity; I'd say activism (fomenting social change) or radical self-sufficiency (e.g., learning to grow your own fruits & veggies, as I have).
This is a major reason why I personally no longer commute to meetings for the most part. I would rather pay off the vet bills for my cat and keep my electricity and water on so I can water my garden, and attend meetings by Skype than drive 4.5 hrs round trip for info I could later get in the minutes & conversations I could've had online or by phone. But that's just me, and I'm an ecoanarchist in my *ninth* year staffing this particular con.
This is also why I am a big fan of closet & thrift-store cosplay. Use what you've got & what you can afford--or what you can make. Yes, I'm a fan of things such as homemade corsets; in fact, Creation Station *at OryCon* is hosting a panel, "Custom Corsets: Construction and Q & A". For those who can learn to make their own, it's a fabulous resource; also a great panel for those who are hiring others to make them for them. I love corsets; they're my favorite piece of clothing, ever. But I have become realistic about my budget. I've had to. Whatever anyone's opinion of what I do or don't pull together for "authentic-looking" cosplay, or Steampunk gear, or SCAdian garb, well, that's their opinion, and I don't have to care about it. But if I overdraw my bank account for aesthetics, in the current economy, that would be beyond ridiculous, to outright dangerous.
So *shrug* everyone should use their best discretion, and put their $ where their personal ethics are.