Your definition, I'd say, is unusual. As far as I can see, quackery really have two meanings. One is stated in the beginning of http://en.wikipedia.org/wiki/Quackery It is a disputed article needing improvement, but it starts
"Quackery is the practice of producing fraudulent medicine"
and thus, if someone believes in what they are doing they are not quacks.
...
If you can show good reasons to believe that homeopathy is a deliberate fraud, that it is illegal in at least a few countries, _or_ a definition of the word "quackery" from a good source where the main meaning of the word supports you then please go ahead.
I got my definition of quack medicine from Webster's.
By your definition medicine that doesn't work is only quackery if the practitioner is intentionally deceiving the subject. I'm sure most homeopaths act more or less in good faith. But I don't see any particular reason to doubt that this is also the case for practitioners of the stuff currently in the quackery category.
Our medical disclaimer notwithstanding I believe Wikipedia should do its darndest to provide people with accurate information on medical subjects. This includes making a clear distinction between quackery/alternative medicine and useful medical care.
I think the alternative medicine and quackery categories should be merged because I don't believe that the difference between them can be defined in a workable way. If there is strong resistance to merging the alt. med. category into the quackery category then I suggest merging the quackery category into the alt. med. category.
Regards, Haukur