Sewbiz don't be too discouraged. It was only one show.
Money is very tight right now for many people. And it seems like the younger they are, the more people spend their disposable money on electronics and new toys. At least that's how it feels in my world.
I know it's nice to have a hobby pay for itself, or at least help to do that, but if you really enjoy making things, I hope you let that influence your life more than anything other people contribute to it....or not.
Maybe finding the best items to sell in your area and employing some of the booth/ sales tricks are the secret as onebyone suggests.
I hope you continue to try, and are able to have more success at other venues.