It's admirable to seed, and the example of 1,000 files is mind-blowing, as I'm hovering around the 100 mark.
As the OP mentioned that he's a long-time member, perhaps there's a "law of diminishing returns" with the age of a file, and its seed opportunities years down the road.
For one, I love the higher resolution files. So unless I'm in the mood for some retro '70s porn, I am less interested in videos that were filmed in 1997, 2003, whatever. There's a lot of great content from those periods, but when the max is like 640x480, it's a no-go.
As well. I think a lot of people simply use the Browse function and scroll the prior week or two. Yes, many older files are "recycled" via the system, but no matter how many times it may surface, I'm still guided by the resolution, as noted above.