> This is such a weird trope.
No, it isn't. Lots of non-trivial OSS desktop applications are clearly made by people with no interest in aligning with expected desktop GUI behavior. From Gimp with dozens of windows to LibreOffice which is slow and has bad font rendering. And those are the 'poster apps' for FOSS desktops, lots of apps are worse.
Instructions unclear. I've kidnapped the GIMP and Inkscape teams and forced them to blend their work into one product.
It now has an ellipse tool, but finding it among the toolbars and menus is left as an exercise for the reader
Depends on your system. A few years ago I ran it on a MacBook where scrolling on an empty page took ages. Seems nobody tried it out on a Mac before releasing the port since it was totally unusable. Hopefully it's fixed now, but I wouldn't recommend a piece of software I don't trust to anyone.
Last time I tried (admittedly two years ago), it was incredibly sluggish, several times more so than MS Office, which is also sluggish in general.
Gimp's single window mode was made the default years ago now, so that's not a great example anymore - there's scientific software that uses that paradigm that might work better, but most of that isn't OSS. Also, Libreoffice being slow and having bad font rendering seems pretty inline with Word nowadays...