When panels started going from 4:3 to 16:10 and then to 16:9 yes, many people complained because they were not better for work than the old style monitors in similar resolutions. They have less pixels than their 4:3 equivalents. 16:9 has been adopted a) because it's cheap as it's the most common size available and b) because it looks 'modern'.
Furthermore, the iPad is only 1024x768 points of resolution, while most desktop monitors are at least 1600x1050. If you have used a computer recently with 700-800 pixels of vertical height, you'd probably agree that it's not optimized for reading vertical content; it's a very narrow window through which to peer. The iPad, in portrait orientation, has much the same vertical height as a full desktop monitor, while not losing anything in the width, as it can only run 1 app at a time, and again, most sites are optimized for a width of 768 points. (Hence why most websites appear as a narrow bar in the center of the screen if you maximize your browser window on a high resolution screen).
A modern screen of 1920x1080 has more height than an ipad, while also offering enough space to place multiple windows side-by side. It's a worthy tradeoff, although the 4:3 equivalent of 1920x1440 would be better yet.
