We only talk to things that have faces

Suppose that the universe is filled with alien life forms, but that we consistently fail to recognise any of them as life forms. Those that live outside of the goldilocks zone, or have drastically slower or faster metabolisms, etc..

We ignore (or hunt, farm, mine, crush, poison, or burn) them because we can't communicate with them and deem them inherently unintelligent.

Within that universe, the only aliens we recognise as "intelligent" will be those that are most like ourselves. It's not that all the aliens are peculiarly similar to us, but that we can only have meaningful interactions with aliens that are sufficiently similar to us.

The rest, we eat.

We only talk to things that have faces

Suppose that the universe has a diversity of alien life forms, but that we consistently fail to recognise any of them as life forms. Those that live outside of the goldilocks zone, or have drastically slower or faster metabolisms, etc..

We ignore (or hunt, farm, mine, crush, poison, or burn) them because we can't communicate with them and deem them inherently unintelligent.

In a universe rich with diverse life, or with technology that allows us to search many different worlds quickly, there's a lot we can afford to overlook before we happen upon something similar to ourselves which we recognise as "obviously intelligent". The more numerous the life forms, the more likely it is we can happen upon something very much like ourselves before being driven to making a serious effort at trying to comprehend the genuinely alien intelligence of creatures we didn't really "get" when we first saw them.

So it may not be that all the aliens are unusually similar to us, but instead that we can only have meaningful interactions with aliens that are sufficiently similar to us.

The rest, we eat.