I saw that this instance had a large number of users so I thought "more users->more content->more fun". Apparently, I had to prove my value by answering 3 questions that showed my interest in their community and my value as a potential future member.
What could possibly be my value to a general purpose instance besides money? I'm a software/cloud engineer so I guess there are things I could help with, but my guess is they were expecting me to say "I can donate".
I get it, they need donations to exist, but this upfront? And to a community I don't even know? Maybe I'm imagining things and they were looking for something else?
Do all instances rely on donations? I'd like to contribute to the instances I enjoy at some point. But only if I feel at home with them, not as a prerequisite to join.
Should've probably asked them. They are trying to be a more curated community. You are expected to read and obviously follow the rules, and reflect that in your short application text.
If it's not for you that's obviously fine. Just like it's 100% within their rights to not want you. Don't make a big deal out of it.