General Discussion

If they are advanced enough to be able to drag their civilization to the maturity point they can travel light-years with little risk, they're advanced enough to recognize what sort of trouble we human beings can be to other life forms. We're effective, self-absorbed little killing machines.
Mind control a few weak individuals who can be anticipated to reach wealth or positions of power into thinking they're Gods, and you can rather quickly get them to kill off enough of their fellow harmful, parasitic species members that it would be easy enough for the world to recover and become a viable, habitable planet for the rest of the inhabitant species.
And maybe a less aggravation dealing with the aggressively muscle headed "adults" who never had to grow up throwing destructive tantrums all over the galaxy because they aren't getting enough "respect" (or adulation).