But we make major, and sometimes irreversible, decisions regularly. We move in with other people as our dps/spouses (reversible, sometimes at great financial/emotional cost) as a leap of faith, that this person is who s/he appears to be (and sometimes in the face of evidence that they're actually a bit wanky).
We take out mortgages, when dp's/our job may be lost/we may become ill/permanently disabled, or mortgage interest rates might shoot though the roof (I remember 15-18%) or property prices might drop, leaving us in negative equity. (Reversible, but at great expense and over a long time.)
On this site in particular, we have children (irreversible) sometimes with unsuitable people (see many, many threads...) which can cost us, and our dc, a huge amount of money, stress, and emotional pain. That's a really big leap of faith, but we make it all the same.
We never really know, for absolute certain, what the outcome of a decision will be.
So we happily gamble with the security of our families all the time. What's the difference here, when the gains of a Yes could be so substantial, and the losses of a No so clear?