I’m German, and I would not want that. German grammar works differently in a way that makes programming a lot more awkward for some reason. Things like, “.forEach” would technically need three different spellings depending on the grammatical gender of the type of element that’s in the collection it’s called on. Of course you could just go with neuter and say it refers to the “items” in the collection, but that’s just one of lots of small pieces of awkwardness that get stacked on top of each other when you try to translate languages and APIs. I really appreciate how much more straightforward that works with English.
It’s about setting expectations. The wording is chosen because they believe that paying open source developers for their work should be the norm, not the exception. Calling it a donation would not do that justice. Their wording is saying “Here’s the software, we’ll trust you to pay us for it if it brings you value and you can afford it”. It’s an explicit expectation to pay, unless you have good reasons not to, which is also fine but should be the exception. Whereas a donation is very much optional and not the default expectation by nature.
In the end it’s just a semantic difference, it’s just all about making expectations clear even if there is no enforcement around them.