Why make future vision videos?

The point of making future vision videos: is there a point?

I can not decide if there is a point or not. On the one hand it is quite entertaining to watch them because, let’s be honest, they are well made.
Some of the future vision videos that I can name off the top of my head are Microsoft Kinect’s, Microsoft Surface’s, Microsoft’s general future vision, Blackberry’s future vision, Touchscreens of the future, 1987 Apple Future Navigator and the list goes on.
It’s like the Minority Report world: all crime is removed with the help of precrime department and everybody gets 20 minutes of peace and quiet during the technology-blaring day. Every surface is a touchscreen, or a motion-controlled device (like Kinect) and connects to your personal devices displaying your information for everybody to see – hey, no crime!
What is noteworthy in the case of Apple is that their vision came true, about 20 years later but it is still a piece of technology that we can go and buy right now.

On the other hand, they are very rather silly. Bad-silly.
I mean seriously, how possible is the removal of crime and vandalism? I’m sure a lot of you have seen Demolition Man, another fine example of the white, Apple-esque future where the police is only a traditional thing of the past.
Also, concerning Microsoft Surface future vision: the technology is released, how come we don’t have MS Surfaces everywhere like promised?
And for the other future visions, even when following Moore’s law, it’s still going to take 20-something years to achieve these dreams. Pipe dreams even.

In conclusion, sure, it’s nice to have these future vision videos but as long as the companies producing them don’t move from the ‘What if?’ genre to the ‘In 20 years, this is what you ARE going to get!’ genre, we will never see this technology.