>> In any sizable JavaScript code base, especially if third-party libraries are used, these incompatibilities can become a very real issue, very quickly.

Whether you use constructor functions, object literals, or the module pattern to structure your code in an OO-like manner, they all result in 'functions hung off objects' which can be called in the same way: object.foo(), I don't see the very real compatibility issue you're talking about.

>> It's very good to see more and more people openly admitting that JavaScript's prototype-based OO approach just isn't practical.

It's plenty practical, I will welcome ES6's class keyword for the clearer semantics, but this is simply vague FUD.