Because investors in Europe are less optimistic.
Why would I invest a lot of money in a company that for it to succeed will have to burn through anywhere between $10-$250 million, before they even think about breaking even?
even as a seed fund, the rate of attrition is genuinely terrible. The only way unicorn can survive is to bend reality long enough so that people are willing to gamble on the pyramid scheme that is behind all non profit making pre-IPO startups.
Think about it. Uber is only in the position it is because it keeps on taking funding. That funding is used to
A) expand at a massive loss
B) Inflate the current valuation
C) pay off previous investors.
If uber were for what ever reason not able to raise any more capital, they would literally collapse over night. They are unable to make a profit without making massive structural changes, changes not scheduled for years. Yes they have cash reserves, but they'll be convertible if some investors need them. More importantly, if an investor decides to sell for a lowerprice, the only thing that makes Uber Uber, its valuation will disappear.
Let me be very clear, There is nothing special about uber. Unlike netflix, amazon, or facebook which either have unique content, or many thousands of hours of personal content, Uber is just a service which can be swapped out at will. It is just a taxi service, one that is cheap because its being subsidised by not paying health care, and the many investors.
It is the very embodyment of the south sea bubble.