Scientists who seriously proposed the existence of unseen worlds were subject to ridicule.
Philosophical naturalists mock unseen worlds until they "see" one and are forced to accept it (i.e. germs, atoms, dark matter, etc.) at which point they vehmently declare they really knew it was there all along and pretend as if they were the first to find it.
It isn't "science" so much as a rhetorical game weighted so they can't lose.
