I read this article recently about how BI users just really love and are used to their Excel sheets for almost anything they do. My first reaction was "duh". My second reaction was that even I used Excel recently to help me data cleanse some contact information.
Its easy to use, the functions are clear, I can develop my own functions in VBA, I can use colors to see problems with values, etc...
I mean I can bet you that "even" if you use MySQL and you want to play around with the data to see if you can find anything, you would use Excel.
But as the article says, there are some drawbacks in terms of time spent fixing errors and if you use Excel sheets that connect to other Excel sheet and then you go and insert a column or something.
Anyway, the article is worth the read and maybe if we could take some of the advantages of Excel and add it to MySQL, maybe we can get some of the marketshare of Excel to move over a bit to MySQL