I think you may have a good point. I agree that they are not a magic bullet cure for anything. I do believe they carry a certain frequency that can affect one's energy field-- especially quartz crystal, citrine, etc. However, I feel these stones need frequent cleansing to remain effective.
As for herkemier diamonds-- I was told that they are the only type of quartz crystal that remains effective without needing any cleansing whatsoever-- and they clear negative energy.
Also, I'm reading that one must keep all the stones exposed to sunlight and not buried in a drawer, to keep them "chugging"!