Some say that humanity should stifle itself, not be so noisy and attract possible alien life. Maybe they are correct.
Evolution produced humanity. As a result humans are violent and react badly to foreign and unusual circumstances.
A planet where life arises and competition between such life forms does not occur would be unfathomable. All species compete for resources against all other species.
Humans have made many advancements. Yet they have carried the ancient suspicions, hatreds, and flaws forward with them. War is still a reality. Violence is an everyday occurrence. Competition is fierce. Hatred of what is different is glaringly present. Tolerance, much ballyhooed, is of scant supply even in those that promulgate it.
Humans must assume all life, should any be encountered of an intelligent nature elsewhere in the universe, is of the same origin and therefore carry the same barbaric baggage.
Although it is more likely humans will encounter machines from other civilizations rather than living forms, even those machines may carry the baggage created by evolution, it having been bequeathed by their creators.