I agree that 4:3 is better for almost everything people use computers for, except watching movies shot in a widescreen format.
Most of what people do on computers is basically oriented around reading: word processing, coding, web surfing. Texts that we read are all oriented to use vertical space. It's incorrect to say wide is better, because we read left to right. Although we read left to right, we scan up and down. Our eyes can only take in so wide a line of text at once. Notice that pretty much all books, newspaper columns, magazines, and printed matter are formated with a much larger vertical dimension.
So widescreen is fine if you have a huge 20" or greater desktop monitor, because then you can have reasonable sized documents side by side and use the extra desktop space effectively. But on a laptop it makes no sense. A 15" widescreen, to say nothing of the 13.3" inch that is so popular now, minimizes overall screen space. Indeed, as simple matter of geometry, you get a lesser overall area of screen space for an equivalent diagonal dimension. The illusion of greater space on a widescreen is just that, an illusion.
The reality is, I think, that long ago Apple introduced the widescreen and it just looked so cool. Everyone started copying it. It's a pure fad. People have fooled themselves into think it's better, but really they just like it for the looks, not the functionality. I just don't believe the people who say widescreen is more useful on a small laptop monitor.
And it makes absolutely no sense that there are no 4:3 laptops left. Can anyone name one? As far as I know the Thinkpad X61 is the only one and Lenovo will probably phase it out soon.
Why are laptop manufacturers doing this? Not because everyone likes widescreen better. But because it's the fad and they don't want to have to make so many different models. It's a business decision which has nothing to do with functionality or user preferences.
Frankly, I don't know what I'm going to do the next time I get a new laptop. I don't want a heavy laptop with a 15" or larger widescreen. But 14" and under widescreens are just ridiculously not useful, in terms of vertical space.