My $.02 worth is a combination of one and the last.
There are times when, even though I take pictures, I don't have time to process them. And too, sometimes I have just the picture in the file but can't submit it because it would be considered too old. Therefore, "old" pictures would help me out a lot.
If the time limit is increased to two months, people would probably get busy and tend to put a thread like this one on the back burner and forget about it; like I often do with the contest thread--I'll get around to it later. Then later ends up being too late.
The last one would be my vote except for the, "I don't have time to take pictures" part.
Janet