Why do people seem to think we could understand anything about an intelligent species more advanced than us?

I’ve always been incredibly confused by the amount of people asking questions like, “Why would aliens visit us when the universe is so big?”, “How could a species advanced enough to travel the galaxy crash their space craft?”, etc. as a means of dismissing any claims of evidence of UAPs/NHIs.

I understand why they’re being asked, as they are genuine and valid questions (albeit frequently asked maliciously), but my initial reaction is always, how could any human possibly even begin to understand anything at all about a non-human intelligent species? It’s not the questioning that confuses me; it’s the presumption that our human framework of understanding could fully (or even partially) grasp the intricacies of a NHI. We have a tendency to anthropomorphize things we don’t understand, especially when the thing in question is another sapient species. It just doesn’t make sense to me. The potential differences between us and a NHI are basically limitless.

And the public perception of aliens/UAPs has basically always been that it is something fictional, a story, a fantasy. Knowing this and then being met with the possibility that it might actually be real? It makes sense to be incredibly dismissive and by extension get frustrated when others focus on it because in your eyes they’re wasting time/money/resources on something that has always been known to be fake.

Not to mention the potential (as I said above, nobody can know for sure) species-altering discoveries that could be made if non-human technology could be studied by the wider scientific community (i.e. solution to climate change, free unlimited energy, etc.) If there is even a chance of that being real, why on Earth would we not investigate so we can know for certain?

Am I just dumb? Or is my confusion justified?