Joseph Meehan writes:

Note: the above includes a direct answer to your question "There is
not a house without them, but some houses contain huge numbers and
other houses contain almost none."

You consider the cooperative extension to be a scientific source? No,
your citations are all just repeating ungrounded factoids. Not one
surveyed and sampled actual houses. You believe without evidence.

I hunted with a microscope through fistfuls of dust bunnies from my
house looking for dust mites. All I found was ... dust.

Good for you, but I'll be someone with a little more skill, better
tools
and determination will find them.

You believe against evidence.

Just what "problem" is uniquely caused by this creature that a
physician could possible diagnose?

Allergic reactions to their byproducts.

Not unique, therefore not diagnosable.