Are you sure that you are not borrowing your usage of the term from musical, artistic or literary criticism, or perhaps scientific and social-political jargon of the late 19th century? Some ill-considered scientific and social-politiacl fashions of the late 19th century use "degeneracy" to connote "avatarism" or "primitivism," which is a usage that is at least closer to the original meaning, however loony their application of the concept might be.
No, The author is quite right here: Decadence is taken to mean "a descent to a lower level or condition, and generally speaking this usage is synoynmous with Degeneracy in commom practice. In modern usage, Decadence tends to also carry the connotation of greater primal causality than Degeneracy, as in the assertion: "Their degeneracy reflects the decadence of their Civilization,"" but this a somewhat inaccurate usage.
Degeneracy implies a return to a earlier, more primitive condition, whereas Decadence denote a state of rot or decay (from the Latin: dēcadere). This is true in both literary and technical usage.
So the usage in this article is quite correct and apt, and your usage - for once - seems quite eccentric.
Degeneracy also has the meaning of a progressive return to a less organized state so that vitality is lost.(An analogy to biological/medical usage). Eccentric usage-possibly, but the meaning was defined. People know what is meant. These people no longer have the energy to clean their hospitals.