You're right in one sense.
Liquidity is one of the most important attributes that a project can have within its infancy. Investors love to have liquidity, sometimes more so than even the long term fundamentals when we are talking about the short term markets.
As a result of IEO providing liquidity to these newly born tokens they can attract short term investors; but does not necessarily guarantee that in the long run a project would succeed. That still depends a lot on the team and developers themselves.