I think ICO is a good investment when the team behind them already has a big name, and their coin is useful for people's lives. Moreover, if the coin has its own blockchain technology, it is an advantage over other coins.
It's not always like you said that big names may scam investors without even knowing that they are scamming them. The cryptoworld is a new era for everybody and there are few people that interact with it very well to establish good startups integrating a coin with a real value; we see tens of members in the team and running a successful ico but there is no prototype or a product so the team even famous names are adding no value. It's so hard to trust an ICO even when trusting the project.