I've previously remarked that

One of the biggest ways by which scientists and science-minded people fail to communicate with laypeople, I think, is with the phrase “there’s no scientific evidence for X”.

Suppose that a layperson comes to a scientist and explains excitedly that he just heard of a new way to [raise children/lose weight/cure illnesses] that works great, and everyone should adopt that method at once!

The scientist replies that she has heard of that method too, but so far there’s no scientific evidence for it.

By that, the scientist means something roughly like “Well, there might be something to it, but the successes that you mention could very well just be coincidence, and it’s really really hard to figure out whether that thing actually works, even if we do lots of careful experiments. So although the thing that you mention could be worth looking into, we really don’t know whether it works yet, and most things like that actually turn out not to work when you do the experiments, so for now we should assume that it won’t work.”

What the layperson actually hears is “I’m going to be all stuck up and holier-than-thou and insist that we do this time-consuming and expensive examination so that the thing could first pass my utterly unrealistic burden of proof, all the while the evidence of it working is right before our eyes and we could finally [raise children/lose weight/cure illnesses] right if we just acted on it.”

And then the layperson thinks, if only you came out of your ivory tower, you would realize that in the real world you do things when you see that they work, not when you’ve wasted years addressing the one in a million chance that they might somehow not work after all.

And then both of them end up marching angrily away and thinking that the other person is a complete idiot.