I think there's an element of that sporting phenomenon involved where you have a system that youknow somehow works - based on results - but you have no idea how. So you get the situation like with many successful athletes or sportspeople where they try and preserve all the conditions that led to their victorious turning point.
These can be lucky underpants, or eating the same meal, or making sure they get laid (or abstaining altogether), or anything. Nothing appears to be illogical when adopting this superstitious appproach - if you think it contributed to your success you'll do everything in your power to make sure that condition is present next time you need to prevail.
Computing is sufficiently complex to defy the ability of many people to fully understand it, and so it can often (I've found) be subject to the same approach. Running a disk scan every day to prevent your HDD crashing. Restarting your DSL router when your connection hangs or fails. Thinking you're safe from HD loss by keeping material in a different partition (laugh, but that stung me at the end of last year).
It's not that long ago we were offering sacrificial blood to our fields to ensure a decent harvest for the year. Perhaps it's in our nature to appeal to invisible, irrational forces. The alternative is to sit on our hands and wait for it to all go wrong.
What a species!