Did you read the article you linked? They are comparing the screen of the mini to that of a retina screen iPad (iPad 3 and 4). Compared to that, yes it is a let down. But it is better than (or as good as) the screen of iPad 2. The pixels are closer together on the mini compared to the iPad 1 and 2, and thus the text is sharper. But, the pixels are not as close together as on the iPad 3 and 4, so compared to those the text is not as sharp.
If you have an iPad 2, you will have no problems with the screen of the mini. Those who have an iPad 3 or 4, may have. I can clearly see the difference, but I can still read on the mini just fine, though I really would prefer a retina screen. The mini is so much lighter and so tiny and feel better in the hand than the larger iPad, that I'd rather use the mini most of the time. But there are times when I need to retina screen - because I read a lot of PDF files that have equations and tiny characters.