I noticed that ICOs that list their tokens on decentralized exchanges can hardly have those tokens hit the ICOs price. Almost like D.Exchanges are killing token price, are they responsible for such
You quite right to some extent. Most of them go below ICO price and they find it hard to recovery. Reasons might be:
1. Low market cap of the D.Exchage
2. The vulnerability of such exchange, in terms of security.
3. People don't want to be put through the stress of private key or linking their account through metamask, thereby makes less people to trade there.
4. Most D.Exchange has only Eth market.
I want to believe when D.Exchange start to have BTC market tokens will start to do better. Some of such are coming up soon.