I too have a problem with carpet beetles. The larva have hairs that many people have a reaction to (contact dermatitis). These casts or skins become brittle after time and if they are disturbed can become airborne as a fine dust which can irritate our sinuses and respiratory tract.
I first became aware of them after inspecting glue traps left for a few weeks under furniture in my bedroom. The larva tend to hide in dark places, while the beetle stage is attracted to light and can be found on or in between windows.
I then found them in my dresser snacking on clothing in much the same way a clothing moth would.
I too have a strong feeling that these insects are in some way a major contributor to our sickness but for me it seems that there is still something missing.
Perhaps we have contracted a pathogen from prolonged exposure to these bugs, or perhaps we are covered in so much of this larva dust that we are a new target for the beetles natural predator, one which remains to be discovered.
The beetles may have introduced these fibers to our environment but I don't think they are the cause of these fibers, there is simply too many.
Recently I've done a bit of research in this area. One insect I found interesting was the adelgid, specifically the hemlock woolly adelgid.
This species creates wool like fibers, has life stages that are barely visible to the naked eye, and because of its environmental impact has seen government intervention through biological control agents, (some that look very similar to the black carpet beetle) and some that are entopathogenic fungi.
Ofcourse this is just speculation and I don't claim to be any kind of expert but if this intervention were to turn out to be the root cause of "morgellons" it would make sense why the gov't would choose deny it's existence.
ww w. maine. gov/ dacf /mfs /forest_health /insects /hemlock_woolly_adelgid_life_stages .htm