Hypothesizing a specific version of alien is a separate thing.
Recognizing there may be no way to distinguish technologically advanced aliens who do not wish to make their presence known is something totally different.
It is equivalent to saying we can not fully preclude the possibility that such of the universe as we can detect was the result of what we might regard as purposeful calculation.
We simply do not emphasize it because it does not appear we have any immediate, either directly or tangentially, productive path towards improving our understanding of whether either is actually the case. So we don't belabor them.
We don't become attached to specific possible answers to questions whose real answers we have no means of identifying.
Recognizing there may be no way to distinguish technologically advanced aliens who do not wish to make their presence known is something totally different.
It is equivalent to saying we can not fully preclude the possibility that such of the universe as we can detect was the result of what we might regard as purposeful calculation.
We simply do not emphasize it because it does not appear we have any immediate, either directly or tangentially, productive path towards improving our understanding of whether either is actually the case. So we don't belabor them.
We don't become attached to specific possible answers to questions whose real answers we have no means of identifying.