The point?
The point of my aircraft models is to save me a trip to the Air Force Museum in Dayton every time I want to see historical aircraft.
There's also the fact that they're handy from an educational point of view: my son's opportunities to learn don't end when he leaves school.
The point of my Sci-Fi collection used to be practicing in my spare time for a "dream job" at ILM. Now that digital models for SF have taken over, it's just fun.
As for the only ship I've finished, the point of that was to get my son to stop bugging me about having a Titanic. He was fixated on the subject about a year ago and insisted I buy the kit.
Overall, I just like building something tangible. That's something we don't get much chance for in "real life." Even if the model is something from a Japanese animated show, there's a difference inside when a modeler says, "I built this" as opposed to "I bought this collectible."