One big thing about GTK is how inefficient with space it is. I like that kind of design in Gnome and stuff where the interaction is minimal and the UI is just about presenting content - but it completely sucks for tool development.<p>Just look at stuff like Gimp and Inkscape - those things are atrociously bad from GUI perspective - huge ugly icons, huge panels with pointlessly large input fields&#x2F;sliders and other controls - the ammount of space you need to scan and is effectively wasted is staggering.<p>It&#x27;s like they want to make GTK+ a toolkit for pretty &quot;two button apps&quot; and &quot;image viewer software with all the controls on the toolbar&quot;. Don&#x27;t get me wrong - I like those designs - but those are of very very limited use - doing anything complex in GTK+ is just a no-go as shown in numerous IDEs&#x2F;tools that use it. It&#x27;s just built with the wrong set of defaults IMO. And I have no doubt that with some work you could reshape it to be much more usable - but the thing is most developers don&#x27;t have that kind of knowledge, time or affinities.<p>If it integrated into native file dialogs and such I wouldn&#x27;t care if it &quot;looks non native&quot; - intellij IDEA looks non-native as well - it still looks great. Can you imagine how IDEA would look like if it used GTK+ controls ...