I'd disagree with the Blender example. I think GIMP and Inkscape are a notch or two behind their counterparts, but Blender can do almost all the things Maya or Max can, with the primary downsides being ui/workflow shortcomings and industry adoption.
I agree here. Blender is professional grade - it can be replace its commercial counterparts if the industry decides so. On the other hand you can't pretend this is the same situation with Gimp.
3DMax, Maya, SketchUp, FreeCAD, SolidEdge, SolidWorks, CREO, CATIA, etc all have a traditional Win95 style UI with menu bar, toolbar and/or ribbonbar.
Only Blender is the ugly swan, that still has this inhouse-style homegrown UI from the early 1990s UNIX where Blender originated. Nothing in a Blender works as expected, the mouse buttons are opposite to everyone else, the toolbars go all over the place and spam the workspace, no tabs, weird floating windows, keyboard shortcuts from hell, camera controls like coded by 5 year old kid, and so on. Even GIMP has a more sane UI, it's actually not that bad at all. But don't get me started on Blender. Blender needs a complete new UI, otherwise it would be such a shame, the program is good but it's very user hostile and the interface has a step learning curve for no reason at all, and the devs see no reason at all to get over their pride and will never change Blender's UI, which is unfortunate. So maybe someone forks Blender and scraps the old UI and adds a sane UI comparable to industry alternatives - it would help adoption of Blender a lot. Sometimes it looks like they get paid to keep Blender lower key, so that Maya and co still can be sold.
