physical - What was the reason behind total transition towards wide screen displays by the manufacturers?

I often hear complaints by users who are not satisfied by the wide-screen monitors and prefer traditional screen ratios of 4:3 and 5:4. Unfortunately, such monitors now are quite rare and the laptops with such screens are completely wiped.

Most of the people to whom I spoke (and I myself) do not use laptops to watch TV broadcasts or HD films because we have TVs and computers with much bigger screens, which are more suitable for the purpose.

I have heard several theories proposed by the disappointed users to explain such an overwhelming transition by all manufacturers to the wide screens without leaving the users any options.

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  Use of TV matrices. According to this theory, the producers of computer monitors switched to use wide screens because of the availability of a lot of of cheap matrices being mass produced for new generation HD TVs. Producing one kind of a matrix for all devices is cheaper than producing one kind for TVs and the other for computers.

  This theory does not explain why the laptop producers also switched to wide-screen, because small-sized matrices are not widely used in TVs. It also does not explain why initially the ratio 16:10 became popular instead of 16:9 used in the TVs. Nor does it explain why TVs mostly use BGR pixel ordering while the computers mostly use RGB (although some matrices probably can be turned 180 degrees).

  
  


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  Cheating. Because the monitors were sold for price per inch of diagonal size, the manufacturers after transition to wide screens could sell a monitor with smaller matrix area for better price.

  This theory does not explain how wide screens became popular on devices where "per inch" pricing makes no sense (i.e. portable devices). Nor does it explain how it is cheaper to buy a 1920x1200 monitor than a 1600x1200 one, so that a person who wants a 4:3 monitor is forced to buy a wide screen one because it is cheaper and then use it with resolution 1600x1200.

  
  


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  Small vertical viewing angles. This theory suggests that the cheaper TN matrix types used in modern monitors have small vertical viewing angles while horizontal angles are much better. So when using a monitor with high vertical size the image at the top and bottom of the screen appears to have the wrong colors.

  This theory does not explain why if a vertical a viewing angle is good for 1920x1200, it is bad for 1600x1200. It also does not explain why high-end medicine and industrial monitors such as Eizo RadiForce who always used matrices with high viewing angles in all directions are also undergoing a slow transition towards wide screens.

  
  
  

So what were the actual reasons behind such a total transition in all areas without leaving a possibility of choice?