I feel that it is important to point out to native english speakers that the word "decadent" shares a root with decay, and simply means a decayed rotten state,

I feel that it is important to point out to native english speakers that the word "decadent" shares a root with decay, and simply means a decayed rotten state, a decline. It is perjorative. There are no implications of 'opulence', unlike the common usage of "decadence" in English as a sort of slang to describe a rich chocolate cake, for example.