I think when you have a mindset of removing the useless (which your columns were at at the time) you have to be prepared to sometimes add things back in. Yes, it is painful, but it is not a signal that the process didn't work. You should expect to sometimes have to add things back in.
We cannot perfectly predict the future, so when removing things there will always be false positives. The only way to get a false positive rate of zero is to never remove anything at all.
The real question is what level of false positives we find acceptable. If you can only cite this one case where it was painful, then I'd say that's evidence your colleagues approach worked very well!
(I think Elon Musk recommends a deletion false positive rate of 10 % as appropriate in general, but it will vary with industry.)
We cannot perfectly predict the future, so when removing things there will always be false positives. The only way to get a false positive rate of zero is to never remove anything at all.
The real question is what level of false positives we find acceptable. If you can only cite this one case where it was painful, then I'd say that's evidence your colleagues approach worked very well!
(I think Elon Musk recommends a deletion false positive rate of 10 % as appropriate in general, but it will vary with industry.)