(in the context of consumer computing)
The unfortunate reality is that because Windows was so dominant for so long you either have to
a) conform to their interaction paradigms to not frustrate users
or
b) create something incredibly polished and simple that it 'Just Works' how users expect it to (ie Apple).
Once you have people on-boarding to your platform you can distinguish yourself and build out your own paradigms, but it takes a long time, and users are unforgiving.
GNU/Linux is fantastic for power users, but the moment a 'normal' user has to edit a text config file, or open a terminal, we've lost them. When they try to do something that they're use to doing (see thumbnails of their files when choosing them) and it's not possible, GNU/Linux stops being a valid alternative.
> I'm not personally moved by a chan board user's gripes about being unable to quickly find their favourite anime memes to post since all their images are `[1-9][0-9]*.png`
You're uncharitably trivialising the author's point. A common user task is selecting an image file from your device (to upload/edit/share). A user will often have many images in a folder and they want to quickly select the one they're thinking of.
There is an almost universally accepted solution (or 'best practice') to this problem, which is rendering each image visually so that the user can select the correct one at a glance (either as a thumbnail view in a file picker, or a literal grid of images as in iOS). GNOME and Gtk have not implemented this widely accepted (in fact, expected) behaviour, despite it being raised as an issue nearly 17 years ago.
Instead you (and others) argue points like "well they should rename and manage their files", "it's just an extra click", "it's not that important or else it would exist already", "its just one inconvenient thing, get over it". And there are conversations to have around those points, but at the end of the day people are going to have a negative experience with the product because "it can't even render thumbnails".
And the point is that this _isn't_ an isolated issue. Every project has something like this (Apple and Microsoft still have these issues), but we're particularly bad at addressing the issue, or even admitting it exists.