I'm not very keen on directed panspermia either, but I believe they are serious and thus try to keep an open mind and watch and wait.
I gave the site as an example because their theory replaces the (Darwin) "Theory of Evolution" by saying that the diversity comes primarily from cosmic seeding and not by random mutation and natural selection. So it appears the cosmic side of their theory cannot be uncoupled from the biological.
To me, it presents the same problem in trying to debate Intelligent Design or Creationism v. Darwin's Theory of Evolution. If the subject is narrowed to exclude first cause, physics, information theory, mathematics, cosmology, chemisty, philosophy, theology, geology, archeology, etc. - the deck becomes stacked such that there is nothing left to discuss but the fossil record.
I understand that panspermia relies upon genetic material from space, but that doesn't make it a "cosmological" theory. It's a biological theory that involves material from outer space ending up on earth. Cosmology is about the large-scale structure of the Universe. Neither panspermia, nor the (biological) Theory of Evolution provide an explanatory framework for the large scale structure of the Universe and how it changes over time.
"Tribune7's" point was to buttress the earlier assertion by "Fester..." that the "Theory of Evolution" encompassed not only the Origin of the species, but also origin of Life and Origin of the Universe.
I have patiently pointed out for many posts now to both of them that this is NOT the case. That said, Panspermia is an alternative BIOLOGICAL theory that happens to involve life in the "cosmos"... but that doesn't make IT a Cosmological theory, either.
And even on that narrowest of points, the evolutionists cannot gain a solid ground with the Cambrian animals and the numerous gaps in the fossil record - exactly where they are most important - speaking loudly against their theory.