featurised bug

Warning message from MS Excel 2010:

In case you can’t read the long thin message, it says:

A document with the name ‘01.csv’ is already open.  You cannot open two documents with the same name, even if the documents are in different folders.  To open the second document, either close the document that’s currently open, or rename one of the documents.

There are so many things wrong with this.

1. Even if they are in separate folders?  Because we all have documents with the same name in the same folder, of course.
2. It’s a perfectly obvious use case to want to open two documents with the same name in different folders, eg January in the 2015 folder, and in the 2016 folder, to compare them.  
3. Someone had to write this message, thereby tacitly approving this unfortunate design decision (or maybe this is a stopgap and they raised a bug report, but it’s still there).

So, what century is this again?