Why so many cars ending up like this

I agree with all of your comments, but what is it worth? My guess is $1,000 could buy it. What do you guys think?

If you could buy all that for $1000, I'd absolutely go for it. Who cares if it's not all there or isn't bagged & tagged. Just find a cheap rusty donor car, put them side by side, and swap all the parts over (while restoring/refurbing as you go of course). It takes hardly any rust repair to add up to $1000, so starting with a rust-free body saves a lot of time and money.