> So.... Since they explicitly chose not to require any payment, there is no moral obligation to pay them. That's the point.
Requirements are about legal obligations, not moral ones.
> Would it be nice? Sure. But "not donating" is also fine.
It's in general fine not to donate to libreoffice. But that doesn't extend to 100% of circumstances.
> "Donations" are, by definition, entirely voluntary. Whether someone using the software under its proper licensing terms is wealthy, whether you approve of their business model, or other factors are all irrelevant.
As a third party I can judge someone for not donating based on their circumstances. It's not irrelevant. The moral implications are not part of the definition of donation.