Panspermia theory?

[Edwardo Piet]

I think they're just following the evidence.

All things being equal it would seem more likely for life to originate locally.

But all things are not equal... there is evidence of meteorites landing here and I'm guessing they've found sufficient evidence to believe it contained simple lifeforms (or the precursors or beginning conditions to simple lifeforms)... so it's more likely life originated elsewhere.

Of course this begs the question of how life began there... but that's still a different question.