Most of bounty hunters are selling their rewarded tokens after the tokens were traded on exchanges. Also some early ICO participants (with high bonuses) are also selling their tokens immediately. This are some problems why most of the token prices drops after the ICO.
You say that bounty hunters sell their tokens at cheap prices when finished ICO and drop prices on the market, does that make sense? so the allocation for the bounty hunters is very small. I'm not sure they can drop prices on the market.
It depends I guess. Some ICOs give more and some less for bounty programs. They might not be the reason 100%, but they certainly are part of the process.