I don't think relying on reviews is a solid guide whether a certain ICO/coin is trustworthy. We need to dig deeper and do a background check on the team behind it. Also, if the team's information is not shared publicly, then that would be a BIG RED FLAG for me.
A lot of developer and project scammers even go as high as passing personal review on the project on the top review sites.
Like you rightly said, if an investor cannot get or find any meaningful information on the project developers or their core team members, one need to deeply think twice before investing in such coin, though this is not the only factor that determines if a project is legitimate and viable, other factors to be considered are out there for the investor to research. Above all, once should invest a certain amount of money once can part away with or easily let go if the project fails.