I think the central problem (aside from the money/manpower/time issue) is that few non-specialty museums have the personnel with the knowledge to create anything other than an aesthetically pleasing arrangement of weapons. It is not a criticism, it is just a fact. For example, I had a very similar experience to BI's when I went to the Smithsonian Museum of Natural History stacks to look at their SE Asian weapons. They did not have the outstanding quality that BI described, be regardless, the weapons were generally in a dire state of neglect and as far as being displayed, there is one dagger, and a case with a half-dozen dual-purpose weapon/tools such as maks and panabas. The curator of the Anthropology collection (which is where the weapons are) is a specialist is in native American culture, and artifacts, and they have no concervators with knowledge of edged weapons.
As Rivkin said, the collecting community is very small, and thus the field of experts could accurately identify, date, etc. edged weapons is also very small. There just aren't enough to go around, and not enough who would be hired by a museum (being "amateurs," you see -- something I always find amusing coming from someone whose "expertise" comes from the same place as that of the "amateur,"i.e., research and experience).
There isn't much point to my post, either. It is just a sad state of affairs. At least some museums put out catalogues of at least part of their off-shelf collections. But many museums have this great stuff that they cannot or will not use, yet they cannot or will not release it and rather let it literally crumble away in obscurity. Such a shame.
