Indeed, but the point I was trying to make was that by that same token, your fixes will also have defects, and sometime it is 'Better the Devil you know'.

As a rule, I find that there always plenty of 'improvements' that I can make to the things I look after, without needing to deal with other peoples mistakes.

A further point would be that most of us have to abide by ITIL or similar, under which the kind of tinkering that you seem to be suggesting would be likely to get you fired.