My two cents, for what it is worth:
Sure, truth can be messier than falsehood. On the other hand, sometimes lies can be much messier, as well. I mean, what can be weirder, or messier, than all of the angels-on-pins theology, which is no more than a bunch of nonsensical falsehoods? The endless twists and turns believers knot themselves up into to defend the weird Trinity idea, or to explain the presence of evil in a world created by a tri-omni God? The truth is so much simpler than that, that there's no God, and people are what they are.
As skeptics, shouldn't we first see if it's even true, that aphorism about truth and "lies", before trying to explain the why of it? Heh, much like the Bermuda Triangle thingy?
Might it be that we are so outraged --- so rightly outraged, so perfectly justifiably outraged --- when falsehoods are believed and not the truth, that we tend to overgeneralize and end up thinking, despondently, or cynically and laughingly, and for no good reason, that falsehoods generally end up getting far more traction than truth?
Sure, lots of people believe lots of lies. But, on the other hand, lots of people believe lots of things that are perfectly true, as well. Which is the more? I don't know! Nor do I know how one might decide that, one way or the other. My gut feeling is that truths-people-believe probably outnumber lies-people-believe, and decisively so.
When we see a lie that has gained traction, then we hold that up as proof that lies gain traction faster. That's some kind of fallacy there, surely? What's it, the Texas Sharpshooter? We tend to forget all those other instances when lies were quashed immediately, or when they got some traction but were soon outrun by truth.
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Heh, no, not suggesting for a minute that I'm fine with all the lies we live with. Certainly it's far too many, and we should do what we can to eliminate them. Just, that aphorism, it's probably no more than just a witticism, that just seems wise without necessarily being that at all.