There is nothing immoral about deciding you’re happy.
I personally think that a much healthier alternative would be to look for a position where one can maintain their physical and mental health, and give back extra income to worthy causes. There are many organizations much more worthy of my time and money than a bunch of managers who are too cheap to hire people for a follow-the-sun support org. But I'll accept a job with on-call if I think the rest of the deal outweighs the negatives.
It's still fair to call out on-call as a negative though. It's something to be aware of when accepting a job and for companies to keep in mind when recruiting.
If those all sound awful, by all means, do something else. But they're tradeoffs that people accept for their chosen job and compensation. My first job I would regularly be in shipyards and offshore for weeks at a time supervising some job. There was a modest allowance after some length of time but it paid better--and was almost certainly more interesting--than some routine office engineering job.
It is when it sends a signal (about the job, market, etc) that also affects others.
All kinds of scumbags have their "personal truth" that justifies their actions too...
That's the problem with on-call: it somehow took on moral undertones. And as a result it does not feel safe to speak out against it.
If on-call was widely seen as a negative (that a few people like because it gives them a sense of importance, more power to them) then there would be far fewer companies pushing for it as the default. As it stands, most people suffer silently for lack of an alternative. And the first step towards change is to make it OK to publicly say that on-call's a negative, a health hazard, and other options exist (though they may cost more).
More generally, free markets are doing absurd things all the time (see Matt Levine) which makes it hard to extend moral reasoning very far without getting the equivalent of divide-by-zero errors. So I don't think we should be all that concerned about how it affects the job market in general when negotiating with an employer. You know what you want better than you know what anyone else wants. Ask to be Paid More (tm) if that's what you want, but if you don't want to, you don't have to and people saying there is some kind of moral imperative to try to become even more wealthy at a faster rate can be ignored.