The point is exactly that; the valuation is completely ephemeral without a demonstration that this business can actually make money. The user stats are great, but right now these guys are underpants gnomes trying to figure out how that crucial middle step. This company makes no money at all.
Why do people not see that every single time, what is so hard to understand about that?
Twitter & Facebook didn't make no money at all either for the first 3 years even, now look at them. If you have millions and millions of users that use your product all the time, you will always make money. It's just a matter of when you turn monetization on, which Snapchat is already testing with sponsored stories.
I hope I mentally parsed your comment correctly, it was tough with all if those negations, but the claim that all companies who have long user lists will always monetize is demonstrably false.
Off the top of my head:
1. Friendster
2. AltaVista
3. AOL's AIM. They tried, and failed.
I'm not saying that a huge user list is worthless, that would be silly, but until you're making money it's all just pie in the sky thinking.