Just for clarification, it's not Consumer Reports' "opinion," it's the result of the annual survey of members who own the car. It's a statistical analysis. For the Niro, they compared the frequency of repairs reported against all other 2017 cars. The Niro performed very well, and placed in the top category of reliability. That's particularly impressive for a new model, even more so considering the hybrid components.
They track each year's model over time and update the results annually. Hopefully it stays at the top!