GNOME's architecture is rubbish: MDI, singleton-itis, cross-document intra-application interference
I just opened a picture using eog. Then I opened a different picture using another eog, or so I thought. It was impossible to interact with the second eog, including moving the window. This turned out to be because the first eog had a blocking modal dialog open about printing. Can you see how wrong this is? This is cross-document intra-application interference, and it is bad. Very bad. Similar problem in Apple's OS X when you switch to a window, and all windows "owned" by that application come to the foreground. Only one of the dozen documents you have open with that application is relevant to the task you're doing, and the foregrounding of the other 11 block out the other information, in other applications, relevant to your task. You thought you were using a windowing system so you could see the information relevant to your task together, but Apple have arranged that it doesn't work like that. True to GNOME's raison-d'être as a very...