> Could you provide some reasoning for such a resolution? 
> I had thought that "won't fix" indicated that the issue
> wasn't actually an error in behavior.

No, that would be "invalid."  IMO, "won't fix" is for bugs were cost of fixing them outweighs the benefits.  Here is a typical example: issue8309 "Sin(x) is Wrong".

Here, however I am torn between "won't fix" and "invalid."  As I said in my previous comment:

"""
Note, however that the problematic behavior is due to D/DT
classes implementor's choice not to derive DT from D.  Whether
resulting violation of the symmetry of equality is a bug in python or
D/DT implementation is at least an open question.
"""

I don't mind keeping this open if there is a hope that someone will come up with a working solution.  The current patch is not a solution.