The Retina display is not the culprit in making newer MacBooks more difficult to repair. The difficulty is the result of several factors driven by public demand for more speed, lighter weight, and longer battery life. I don't have any statistics, but the engineering involved would suggest repairs are less likely. The downside is if repairs are needed they will be more difficult and therefore more expensive, or even impossible.
IMHO AppleCare is a requirement not an option
