Your view on that is spot-on and one that Spielberg has gone on record as saying that had he made the film today, he would never have the father leaving his family. Even though this scene was something that I picked up early on as a kid as being wrong, it still doesn't lessen the movie for me. I think because I was a kid that I didn't really have to lock in on that part of the film because I myself was wanting to discover beyond this world and I could relate to his obsession somewhat.