It’s not mysterious, nor rare, and it's not caused by "technical difficulty." It's caused by people: the loudest, neediest, most entitled LiGNUxers who treat volunteer developers like slaves.

When one tiny project collapses, it can bring down multiple others.
Ueberzug is the perfect case study.

FOSS developers start with curiosity, passion, desire to solve a problem, and pride in building something cool.

What they end up with is demands, complaints, entitlement, “fix this now”! -Rarely "how can I help?" They're attacked by users who don't read their README, think "Free" means they're owed something, and those that file bug reports with no logs attached!

The more useful the project becomes, the more abusive the user interactions get.

Ueberzug was a small Python tool that let terminal apps display images.
Not a huge project, corporation or even a team.

But because it worked so well, it became a dependency for file managers, terminal image viewers, screenshot tools, previewers, collage generators and the only thing I left that I preferred on Linux: ucollage

This one developer was responsible for keeping dozens of other projects functional, and they fell to the constant complaints, demands, and accusations. They quit, not because the code was difficult to maintain, but because of the users! -This doesn't typically happen with paid developers because at least cash is rolling in and complaints would be more justified.

The snowball effect when one FOSS dev quits

One single FOSS dev can cause breakage across multiple tools, forks popping up, downstream devs scrambling (with users yelling at them now), more burn out, more quitting.

LiGNUxers make it worse (when they think they’re helping). -Demanding features, arguing about principles, lecturing devs, insisting on ideological purity, and treating maintainers like employees. It's not support, its pressure, stress, and unpaid emotional labor.

Ueberzug is just the poster child because it was small, fragile, and widely depended on. It was a backbone for my favorite image viewing program, and losing its use for uCollage helped me move on from Linux.

Here are some other real life cases that apply:

ImageMagick is used by everything: web servers, desktop apps, scripts, packaging pipelines, CI systems. Every few years, a maintainer quietly disappears. No drama. Just burnout.

youtube-dl (DMCA drama + user entitlement). When youtube-dl was hit with a DMCA takedown, users screamed at the maintainers, demanded instant fixes, and treated them like a free streaming service. Maintainers were already exhausted from constant site breakage, entitled and poorly written bug reports, and people demanding support for obscure sites. Several maintainers stepped back permanently.

OpenSSL -Before Heartbleed, OpenSSL was maintained by one guy on a shoestring budget powering the entire global internet. The maintainer was burned out, overwhelmed, and blamed for the entire mess. Corporate funding only arrived after the catastrophe.

LeftWM (Window Manager). The developer publicly quit after endless feature demands, users complaining about “missing” features, people insisting he rewrite the project to match their preferences. He explicitly said the community’s entitlement killed his motivation.

mpv is the best media player ever made imo. It’s notorious for users demanding features, arguing with maintainers, and lecturing maintainers about design decisions. Several maintainers have quit over the years, citing: "burnout", "toxic interactions", and “I’m tired of arguing with users who don’t contribute anything”

PulseAudio -Poettering didn’t quit FOSS entirely, but he did leave the Linux desktop world behind, along with all the harassment, death threats, endless complaints, users blaming him for every audio issue, and distro maintainers shipping broken configs and blaming him! He eventually escaped Red Hat and went to Microsoft to work on systemd‑related tech in a calmer environment.

systemd devs have repeatedly stepped back or reduced involvement because: "every change triggers a flame war", "users treat them like villains", "they get blamed for distro breakage they didn’t cause".

Audacity maintainers were exhausted. They sold the project to Muse Group. Users accused them of “selling out”, attacked the new maintainers, and spite forks popped up. The old devs burned out and the new devs did too. -LiGNUxers weren't learning from their mistakes.

Similar stories exist for:

• GIMP has had multiple maintainers quit or go inactive
• NPM Maintainers (left-pad incident)

and office suites:

• LibreOffice -Chronic maintainer fatigue
• Apache OpenOffice - Mass maintainer exodus
• Calligra Suite (KDE) -Maintainers quietly dissappear
• AbiWord -Burnout, stagnation
• Gnumeric -Burnout
• Only Office / WPS -Sellout

Linux project dies as Linux user repeatedly bombarded the dev with attacks

I could go on and on...

Do I feel bad for OS developers? -Not really. They are their own enemies killing their own paid development jobs and perpetuating entitlement. Sorry, they have to learn the hard way. They're a lot like LiGNUxers -Their Own Worst Enemas!