It's not useless. It is actually the premier communication platform for emotional content at the moment.
Think about that.
Think about that.
In re "is this just 'damn kids these days' speak", no, I suppose I'm one of them. But if a picture's worth my while then don't make it arbitrarily temporary; if it isn't don't send it at all.
It makes no difference to me whether or not shapchat succeeds, just as it makes no difference to anyone whether or not you get their snapchat message.