It was released in June because, as an action film (as well as a Christmas one) it fits with being a Summer blockbuster, so the studio most likely went for the summer release.Only a third of polled people thought so, so fire that market exec, he's a bit thick.
Die Hard, known for it's small budget, didn't think it was right to release it during December, which in modern cinema is a bigger month than June, despite being a Christmas film. Makes perfect sense!
Remember, it's the studio that's most likely going to determine when the film is released, not the creator... Who may well have wanted a December release.