@izzythepush,
Nobody has claimed there is no room for doubt, but us humans rely on some evidence to assert that something must exist. Nobody tries to prove a negative, because humans are not capable of proving such
Only positive assertions can be proven. Negative assertions are mostly impossible to prove.
Saying I don't know to the assertion that there aren't 10000 elves flying around mars is that person's problem. There's nothing to be proven, and there is no burden on the person saying there aren't 10000 elves flying around mars, because most people understand it's only imaginary. It's not a positive claim.
If I assert there are 10000 elves flying around mars, the burden of proof falls on me, and I must provide evidence for such a claim.