Yes, and in this case the designer made a (hopefully conscious) decision that usability was more important to the user than the information that an attacker wou

Yes, and in this case the designer made a (hopefully conscious) decision that usability was more important to the user than the information that an attacker would gain. These sorts of decisions are the hard part of building web applications; there's no right answer applicable to all situations, you have to use judgment and experience to gauge how to balance the competing needs of your users and your business.