My largest criticism of GraphQL is that it doesnt go far enough. That is to say that I want my components to declare their data dependencies, but not all data comes from a server. Some data is computed, other data comes from different servers, and some other data is locally generated. For example, facebook has some user information that I want to add to my User object; in my case, theres no reason for the component to know that its data is actually coming from multiple sources but I have no simple way of coding that.

Another issue: there currently are a lot of servers that are REST and it would be really nice if there were ways of incorporating them in the GraphQL schema. One of the most useful features to add here would be ways of linking separate REST objects to each other in the GraphQL schema. This would help adoption quite a bit.