In a traditional web app, we have 4 layers: client views, client app, server app, database. React, described as a strict view layer, in reality is being used as much more. At this point, it is not just consuming the client app, but is also taking nibbles at the server app as well.
To each their own of course, but i would ask people to hesitate about these decisions. The architectural issues with monolithic views is well known, and just because we have a shiny new tool does not mean we should throw that understanding by the wayside.
Source: i work full-time on a React and Backbone app