It's not trivia. If someone doesn't know the difference, they're going to allow bad data into our database. Large webapps with poor model validations are security and maintenance nightmare.
Actually, I am reminded of an error that happened which was similar to this. After I left a past company, an engineer flubbed a validation which allowed a subtle bug to go undetected for 10 days which cost the company $500,000.
No, money wasn't being stolen, but the validation error meant that clients' money was being spent and not being tracked. The company had to eat the costs.
$50,000/day is an expensive lesson!