Well, SDL 2.0 has been out for a long while now and although I have never used it from what I have heard it's much better than its predecessor. You cannot really expect deprecated stuff to remain around indefinitely.
Also, I now have the strong suspicion your unresolved externals have a very different source than linking or not linking SDL mixer. Most likely it depends on some Windows multimedia functions which you have to link as well. Of course that would have been immediately obvious had you posted the actual error messages. Which you unfortunately did not.
On a personal note, this is the second time you go towards blaming the tool in this thread. A decent programmer does not blame the tool until he has understood the whole problem and exhausted all options. Placing the blame on the tool early and often is a good way to tick people off and receive less and less help in the future.