It is assumed that for any market to be efficient all market participants should have equal access to information. In real life though, this is never the case and will never be. So those who are more informed will always have an advantage before those who are less informed (or more misinformed, lol), and free market (a total laissez-faire capitalism) can only make this situation worse, since there is no impartial arbitrator by definition (whose role is usually taken by the state)...
In short, everyone is manipulating others to the extent of their misunderstanding, and being manipulated himself to the extent of his own misunderstanding.
Short answer: it's profitable, short term, to manipulate people, be it markets or commodities, which is probably what's being done right now with some altcoins: the pump & dump; the buying of one's own coin on one's own market, boosting price; you name it.
Capitalism is like a magic trick: it isn't what is actually good from an engineering- or environmental standpoint, but how much one can deceive to make it look good. RealBitcoin suggested independent journalist and reviewers; but how do we know they aren't being manipulated as well, or are doing it themselves, or getting paid to do it.