Excel is a great case study. Turns out, if you give people an accessible and widely available Touring complete environment, they will manage to do pretty much anything with it. On another note, it's interesting to observe that the problems spreadsheets have are the same problems that plague poorly designed software everywhere - lack of documentation, lack of testing, lack of input validation, among others.
This is pretty much the same reason that PHP is much maligned - it certainly has gotchas but they're not so much dangerous than, say, the C++ gotchas... When everyone is able to "have a go" at a tool they'll all abuse it in their special way to get things done and good on them for doing it since if every data problem required an engineering team to solve everyone's business would grind to a halt.