My variation of the Fermi paradox:
“Any civilization stupid enough to emit radio signals into space will be quickly destroyed by enemy aliens.”
Much of Science Fiction presumes that aliens are necessarily:
1) Much more advanced than us technologically.
2) Much more “advanced” than us sociologically, and therefore “peaceful” “enlightened” and “benevolent” ... ie, Space Hippies.
(1) Sort of makes sense if they’re visiting us ...
(2) Is absurd on so many levels as to boggle the mind. You get to be the top of the heap on your own planet by being the baddest badasses in the joint. When (if) you go traveling the stars, you’ll go out as the complete badasses that you are.