Most of your points also apply to open source software, and aren't strict requirements for proprietary software.

- discontinued: Atom just got discontinued. It's open source. Photoshop on the other hand has withstood the test of time.

- Audacity's 3.0 update removed a feature I relied on. I wasn't forced to update to it, sure, but proprietary software doesn't force updates either.

- Being able to fix your own bugs is a great part of open source! But not something most professional software developers really expect to do for their IDE.

- open source formats are probably more resilient than closed source, but I would argue many proprietary formats are also pretty resilient. Code is also based on plain text at it's core, like latex, so it's always going to be pretty resilient.

- you'll never have a guarantee that a tool you invest time in or money in will be the leading tool in five years.

> discontinued: Atom just got discontinued. It's open source. Photoshop on the other hand has withstood the test of time.

But if I want to use Atom I can fork it, or keep the source around. It doesn't go away from my environment until _I_ say it does. And Photoshop has become more and more user hostile over time.

> Audacity's 3.0 update removed a feature I relied on. I wasn't forced to update to it, sure, but proprietary software doesn't force updates either.

It is impossible for libre software to force updates, and quite possible for proprietary software to do so. It's part of what pushed me away from Windows in the first place, and other apps (especially web, but also other stuff) also do so.

> Being able to fix your own bugs is a great part of open source! But not something most professional software developers really expect to do for their IDE.

While it isn't expected, it's definitely a nice-to-have.

> open source formats are probably more resilient than closed source, but I would argue many proprietary formats are also pretty resilient. Code is also based on plain text at it's core, like latex, so it's always going to be pretty resilient.

But with libre software, I don't have to wonder. Even if a project uses an obtuse, obfuscated binary format I know I'll still be able to read it (with a little prep work). With code this is less of an issue - as you note - but you did mention Photoshop earlier, so I'm assuming we're talking about software in general.

> you'll never have a guarantee that a tool you invest time in or money in will be the leading tool in five years.

I don't need it to he leading, I need it to be around and functional. Pretty confident Emacs/(n)vim will be here a couple decades longer at least. I believe this was GP's point - that it's better to worry about what will work best in 10 years, not what's standard now.

> But if I want to use Atom I can fork it, or keep the source around. It doesn't go away from my environment until _I_ say it does.

This is technically true, but in 99% of the cases is not realistically true. Most developers who use said FOSS external dependency do not want to actively maintain it themselves.