Not at all. The team that has listed a token on some centralized exchange can also scam exit at any time, so their true intentions matter.
If the source code of the token smart contract is published, then investors can inspect it and find out what part of the funds is allocated to the developers. The team can pull the rug but the maximal amount of their coins is predefined. In my opinion, people should only invest in projects backed by the team they trust.
Etherdelta (Forkdelta) is a decent decentralized exchange based on a reliable smart contract. Any ERC20 token can be traded on this platform. Uniswap is the next generation DEX that requires a token listing. Version 2 consumes a lot of gas and is more expensive. These DEX types differ significantly. It is impossible to drain the liquidity pool on Etherdelta.
Scammers can use any exchange. I do not blame Uniswap.