1. Using IEOs instead of ICOs, we are adding a 3rd party than can control what we buy. This is in contradiction with the main purpose of cryotocurrencies which is centralization.
With a centralized system it means that the value of transparency is almost non-existent (unless the exchange wants to open transaction data for anyone or any wallet that bought during the IEO).
4. Exchanges might get money and do not pay attention to healthy of the project like what they do for listing the tokens
Sure, they (exchange) get some money from the project and most of them (
in my opinion) they don't even doing some deep research about the project who will do the IEO in their exchange