> And then one day you realize there are bugs duplicated all over the place and you pray that nobody hits them.

If you can copy-paste repeated code, you can copy-paste debugging as well.

Duplicate bugs are a single bug.

Obviously not all DRY is bad.

And then I can explain to my boss why I'm working on stuff I'm not supposed to when I could have just wrapped it up once in a library and fixed it once on all those projects.

So now not only have I created a bug, duplicated it N times, but my boss thinks I'm an idiot and wasting time for not applying DRY and good engineering hygiene.