No one is arguing that. Investors are valuing Uber at $17 billion, which means future value, not current worth. I know you know that but many people seem to be confused by high valuation by looking at current revenues which is weird from supposedly tech bloggers. And you're right about its future in logistics too. Huge potential there.
While other companies like Satellite companies are selling in the hundreds of millions, not billions.
I don't think these gross over-valuations are sustainable.
These are all companies that a few years back, would have, at best, sold for a few hundred million.
No it doesn't. The value is today. If it was some future value different from today's value, then someone would be arbitraging on the difference.
Maybe you are trying to say that the value today is based on future performance, which should be obvious.
They will want to make a profit, so they must assume the company, some time in the future, must become worth more than that (stochastically).