Tenants in this parlance bothers me also because of the obvious misuse.
One could, however, claim misspelling of the old 1600s spelling (tenent).
Tenent was the common spelling in the 1600s for tenet, which was defined as a belief or principle. Today it is a common misspelling for either tenet or tenant, which are defined as someone who rents a space.
Few people even know the correct spellings of 400 year old English words. The truth is, we have an epidemic of illiteracy in this country.