I've found that many technologists that are in the business of writing code don't understand the extreme ROI of commenting code properly. In a previous company where no code was documented, it would take an average of two days to find and then research a major proc that needed to be upgraded. I made the rule that if you touch the code, you must also document the code. After about a year, not only did the research required drop from 2 days to somewhere between 20 minutes and 2 hours, but the amount of code sent back by QA for faults went down from an average of two returns to nearly zero across the board.
And to be sure, comments like "Update the Customer table" are totally useless. I tell people that if you remove all of the code, the comments that remain should be sufficient to allow you to create a functional flow chart.