Actually the old-school CRT monitors were much narrower even than 3:2 (1.5) - they were 4:3 (1.33), just like NTSC television, and very close to the very-old-school "Academy Ratio" in the movies.

Which is the reason the movie business invented wide-screen: To make their movies darn near unwatchable on standard television. HDTV went wide-screen to chase the movie business, which has in response pursued ever more extreme ultra-wide ratios (12:5 or 2.40 in not-insane notation) for their blockbusters, so even with a brand new wide-screen HDTV, you get letter-boxing and only partial vertical resolution when you watch the latest Batman movie or whatever.

Now there are some small movements in the direction of ultra-ultra wide-screen in the computer business, and it doesn't bode well. [1]

So it's Hollywood's fault that your computer screen has a stupid shape, just as its Hollywood's fault that it has a stupid interface (HDMI/HDCP), too.

[1] http://www.cnet.com/laptops/toshiba-satellite-u845w-s410/450...