It literally isn't, changing/reversing a premise and not adressing the point that was made is not a valid way to counter the initial argument in a logical way.

Just like your proposition that any "small" chance justifies investing "everything" disregards the same argument regarding the precautionary principle of potentially devastating technologies. You've also slipped in an additonal "with no real downside" which you cannot predict with certainty anyways, rendering this argument infalsifiable. At least tsimionescu didn't dare making such a sweeping (but baseless) statement.