Maybe I'm just being too grouchy. This editor looks impressive.
(I don't know the developers)
And yes you are right, as developers we tend to publish useful stuff more often for free than not. But maybe it stems from our inability to market cool applications so that we get money for them.
The single greatest benefit of having our skill set is that we are capable, in a way that few other people in the world are capable, of single handedly building products that we can sell for the kind of money that frees us from needing to work for other people. We can quite literally create our own destiny.
And you would throw that away.
I can't even begin to fathom why you would want to live in that world.
Having a software product as income source means you don't have to have a day job working for somebody else. It means you can spend your time doing whatever you want, be that working on your own personal projects, surfing, traveling or, yes, earning more money. You can even choose to build open source Mac text editors and give them away for free.
It's your choice what to do with that freedom. The important point is that we, as software developers, are essentially handed that freedom by nature of our skill set.
That's a really cool thing. So while I can see an entitled end-user saying something like the grandparent's "you already have a job that pays you, so give us the output from your nights and weekends for free", it's surprising to see that attitude from somebody who would be most impacted, were that to become a reasonable expectation.
Some people crave the recognition a successful open source project gives.
Some want to learn something.
Some want to give a gift to the world.
Some don't want the hassle of supporting software.
Some believe "from each according to their ability, to each according to their need"
One explanation, like you point out, is that they are free to work on a project such as CotEditor because they are financially secure.
That's assuming that it's a program written in C/C++. If it's another language then you might have another huge hurdle to go through. (Properly installing Go in my PATH took me a while). That's also assuming they don't rely on IDE-specific make files. A lot of the time OSX applications rely on xcode project files. The other day I was trying to compile an Android app before realizing that it was written in a language by Adobe which required the purchase of a full suite.
Open source can be really limiting if the developer doesn't make an effort to document the build process well and doesn't use open tools to create the product.
I don't think users respond well to this either. You're essentially splitting your userbase into a group of people who know enough to build it themselves and receive it for free, and a group that have to pay, and I don't think people in the latter group appreciate being in that group.
As for your second point, I think it comes down to two things: if the user's time is more valuable than their money, and two, if they can get support for the paid product (at least that's how I've seen some products doing it), so it's not as if the paid is without it's benefits. Your Hexchat example shows how important it is to not alienate your users though.
But I won't be using Chocolat anymore, after they pulled a bait-and-switch so that Version 2 can't be used without you paying for version 3.
Bad dev, no cookie.
I'm very afraid the government would one day impose a minimum price for everything, and poor families will never have a shot at any productive activity and will just stay poor forever.
In my country, they voted a law that bans free newspapers and imposes a minimum cost of about 50 cents. Why limit access to knowledge and the effects of a free market? This is the whole "job creator" logic all over again.