I don't think it is rational since it appears to be self-refuting. Claiming that it is "rational" just begs the question, "based on what evidence more than your subjective feelings".
And you can disagree with it pretty easily without fallaciously accepting that "we can assert anything making it just fact".
For example, something can be asserted without evidence and not dismissed. If an evolutionary biologist explains to you that Tiktaalik can be reasonably accepted as an evolutionary fossil demonstrating some sort of transition, you can accept it without having actual evidence for it. You accept it based on the authority of the evolutionary biologist. You are of course then welcome to go and look at the evidence yourself. Point being, you did not dismiss it just because there was no evidence, you accepted it based on authority despite not being presented without any evidence.