There is a lot of talk among photographers that "memory is cheap," referring to the ever decreasing cost of memory cards and hard drives. The thought being, since memory is so cheap, photograph anything and everything and keep it forever. Sometimes we find that a long overlooked photo is really good, and, years later, uncover its true potential. OK. That happens. But, much more commonly, good photos never get discovered in the morass of all those unedited files kept because we made too many photos in the first place and then didn't delete them when we had the time and energy.
Memory may be cheap, but our creativity isn't. For me, choosing to work on a few really good photos is much more likely to happen if they aren't buried in hundreds that should have been deleted months or years ago. If I cannot bring myself to search through thousands of files to find what inspires me to move ahead, then I'm seriously impeding my own progress.
There are limits to how messy a desk can be before we just give up trying to find anything. Even well organized piles become obstructive when they get too high. Same with photos. I am much more productive when I can look through a few good images to find the one that I want to process than when I try to plow through hundreds. I just lose the motivation. Motivation and creativity are not cheap. To me, that's what matters.