1: Miners mine in giant pools to get the best reward rate
2: Traders, For the most part, are Dumb and prone to manipulation resulting in selling off coins with small price drops.
On a positive note, Satoshi will inevitably hail in the permanent revival of cryptography as a whole
TL:DR; It's kinda sad how beautiful ideas can die.
1: That makes perfect sense; but pools will prevent getting too big, because it would treaten the whole bitcoin network, and that's something they wouldn't ever want.
2: I don't see how bitcoin traders would be any more stupid than other traders. All traders in general are prone to manipulation, resulting in selling off coins with small price drops. It's a very typical scenario.