Can someone explain something to me?

I have a bunch of different excel spreadsheets that include queries to
a MySql database. Recently, our IT department was upgrading some
systems and the MySql database was moved to a new server. For various
reasons, this new server has a different name than the old server.
They informed everyone of the change and asked them to update all the
references to the old server.

"No problem," I thought, "I'll update the DSN that refers to the old
server, and everything that connects to the database via the DSN will
simply start using the new address."

As it turns out, it is a problem.

From my research on the web and some investigation on my PC, it
appears that Excel likes to save a full connection string in the XLS
file. This includes both the DSN (which contains the connection
details like server address) AND the full server address. Then it
ignores the DSN from that point forward.

Now, as I said, I've done some research, and I've found a couple of
solutions for this problem. I can fix it, but they all suck and I'm
not going to enjoy it.

My questions are simple:
Isn't the point of the DSN to make changes like this simple and easy?
This is a pretty basic concept in software development - save a
resource in one place, so you only have to change it in one place. Why
did the folks at Microsoft decide that it was important to save this
information in the Excel file?