the only ones i ever removed was one hdr that looked like the room was on fire. one where a guy said either give me a print or erase it. i think a few were too noisy to repair. i've fixed about 3 dozen of them or more. and i didn't upload batches of stuff when i first signed on.
my feeling is, when i upload things, i only upload my best work. naturally i get better over time, but as long as it was my best then it stays. if things bug me, like stuff i couldn't clone out then. or i like the image but it needs more story, its reworked. like i always like candles lit in pictures. but at the time i didn't know how to light them digitally, but now i do. so i go back when i see it and repair them.
---Mike Savad
MikeSavad.com