You've hit the nail on the head. The journal's impact factor would be pitifully low. But you're quite correct that having the information available would save a great deal of time and money (and blood, sweat, tears, grief and anxiety).
The ability to publish negative results would be tremendously useful for doctoral students. I mean, a tremendous amount of science is negative results and nothing about dissertation research guarantees that your hypothesis will be proven by your data. This would ease a lot of the angst caused by publication requirements for doctoral students and would give them phenomenal writing practice on fairly low stress publications. There's merit here, without a doubt, but it doesn't fit in to the established hierarchy of academic research which is a massive issue. I'm a firm believer is reform of academic research, but that's an entirely different discussion...
Perhaps a different standard of publication would be required. It should be very easy to create a negative result publication, but the real kudos should accrue to people who repeat a negative result that has great value to those who subsequently avoid the result if you see what I mean. So, initially "this is negative" then "are we really sure it's negative" followed by "it's really negative, we all agree, well done to us" or something like that.
The ability to publish negative results would be tremendously useful for doctoral students. I mean, a tremendous amount of science is negative results and nothing about dissertation research guarantees that your hypothesis will be proven by your data. This would ease a lot of the angst caused by publication requirements for doctoral students and would give them phenomenal writing practice on fairly low stress publications. There's merit here, without a doubt, but it doesn't fit in to the established hierarchy of academic research which is a massive issue. I'm a firm believer is reform of academic research, but that's an entirely different discussion...