while i don't feel comfortable leaving my prop to begin with, only leaving it for a few hours would be MUCH better. another thing is that most of the props probably go with a cosplay so cosplayers would want to have them for their cosplay.
The idea was that you would show off props that may or may not be for the cosplay you did for the show.
The prop contest was/is different as the prop is judged on its own merrits outside of the costume it is associated with, and by removing the person who built the prop's identity it adds a level judging annonimity. Think of it, you submit a prop for judging and no one knows who's prop it is. It is just a number, no name to be filled in. So, you could be competing against "Super Famous Cosplayer X" but you wouldn't know it absolutly. Thus a reputation is no longer a factor.
The other idea was to supply a safe place to display the props. Realistically, when you do the comparison between modelers and cosplayers they both are very protective of their work. Actually, at times I'll say the high end modelers are may be more protective. No offence to cosplayers. Most props aren't extremely fragile that can break with the slightest movement.
It was funny, that cosplayers this year could submit a prop up until noon Saturday to display for judging. Again, that goes back to the "I didn't know about it" we all discussed earlier.
But, we have now covered that the display for judging time is an issue for props.