Comment by zamadatix

Descartes would like a word as well, I'm sure. The big difference in the impact theory story is it's the first time we had enough evidence about any of the possibilities that widespread consensus (but not universal agreement it is the sole possible cause) was reached. Prior to that we weren't really sure if we'd even be able to get to that level about it. At least if the theory is replaced it'll be about something we see even clearer evidence of instead of "I dunno, could possibly have been...".