Emphasis on "need" added. What it eliminates is the need to trust a middleman. If you want to go through a middleman, for whatever reason, that should be fine. I would very much doubt that Satoshi would be against freedom of choice.

And that should answer on all the topics about "Bitcoin failing because majority of people leave coins to exchanges". People are free to do whatever they want with their coins, and their preferences change nothing about the network, or the concept.