That depends. If company positions itself as "money for the sake of money", then you are right - being loyal to such idea is weird. But some for instance are interested in advancing other goals (example: https://www.mozilla.org/en-US/about/manifesto/). Does it make sense to be loyal to such goals? I'd say yes.
It's dangerous, however, to allow an employer with "mission fit" to get away with things you wouldn't take from another employer.
For instance, in recent years, in the US, we've taken a hard stance that interns who perform essential job functions - which basically all interns do - must be paid. Should this requirement be relaxed for a non-profit? How does the way I feel about that change if I'm a donor to that non-profit? I care about the mission, but I also care how we get there.
I'm fairly sure that internal to Mozilla, Wikimedia, ahem the Association for Computing Machinery (promoting computing as a science AND a profession!), and any other non-profit corporation you can find a lot of the same internal struggles that employees everywhere face.
Further, you have a leadership team who believes it's OK to pay people below market because they "love" and "are loyal to" their job.
It works for a lot of people, and I know / have known a lot of folks very happy with such choices, but it can be a dangerous alleyway to wander down as well.
Just for the reference, Mozilla (as a company) is not a non-profit. It's Mozilla Foundation that is non profit. But Mozilla (company) is the primary backer of Mozilla Foundation.
Other than that - I agree and fully support fair compensation for work.
My point was less aimed at Mozilla itself than in general at companies / non-profits with a community-oriented mission. At some point, they still have to balance the books.
I'd like to take this moment to point out that Mozilla is a community, and not a company. The community called "Mozilla" is supported by the Mozilla Foundation, which as a foundation and not a company, can actually hold goals other than "money for the sake of money". The Foundation also controls 100% interest in the Mozilla Corporation, which means that it's not beholden to any interests other than the Foundation's and so it can stay pure.
I'm not sure how to keep a company pure short of controlling 100% interest, and I'm increasingly thinking that there is no way to do it. As soon as you let external shareholders in, you are beholden to their ideas of what the company should be doing. And the vast majority of the time, that thing is making "money for the sake of money", because that's the only reason the shareholders are putting up their capital in the first place.
That depends. If company positions itself as "money for the sake of money", then you are right - being loyal to such idea is weird. But some for instance are interested in advancing other goals (example: https://www.mozilla.org/en-US/about/manifesto/). Does it make sense to be loyal to such goals? I'd say yes.