From the start, I’ve always said the same thing: Bitcoin is an experiment and like all experiments, it can fail. So don’t invest what you can’t afford to lose. I’ve said this in interviews, on stage at conferences, and over email. So have other well known developers like Gavin Andresen and Jeff Garzik.But despite knowing that Bitcoin could fail all along, the now inescapable conclusion that it has failed still saddens me greatly. The fundamentals are broken and whatever happens to the price in the short term, the long term trend should probably be downwards. I will no longer be taking part in Bitcoin development and have sold all my coins.

Source: The resolution of the Bitcoin experiment — Medium